Improve Vision

• Any condition affecting the eye is classified as an eye disorder. Eye disorders can affect any part of the eye, including the eyelids, eyelashes, iris, pupil, lens, and the sclera (the "white" of the eye). Nerves, muscles, and blood vessels that surround the eye can also be affected by eye disorders.
• Eye disorders may include any of the following: vision problems, including astigmatism (vision difficulties due to a football-shaped cornea), diabetic retinopathy, myopia (nearsightedness), or hyperopia (farsightedness); conjunctivitis (inflammation of the conjunctiva); uveitis (inflammation of the uvea); keratitis (inflammation of the cornea); xerophthalmia (dry eye); glaucoma (an increase in intraocular pressure); age-related macular degeneration; and cataract (an opacity that develops in the crystalline lens of the eye). Some of these conditions, such as astigmatism myopia, glaucoma, macular degeneration, cataracts, and retinitis pigmentosa, have been linked to genetic abnormalities. Treatment and prognosis varies, depending on the specific condition.
• Please see individual Natural Standard condition monographs on glaucoma, cataracts, retinopathy, and macular degeneration for more information on these eye disorders.

• Vision problems: Symptoms of vision problems include vision loss, altered eye movements, eye pain, visual field loss, bulging eyes, double vision, and headaches. Eye symptoms may involve changes in vision, changes in the appearance of the eye, or an abnormal sensation in the eye. Eye symptoms typically develop as a result of a problem in the eye but occasionally indicate a problem elsewhere in the body.
• Conjunctivitis: The most common signs and symptoms of conjunctivitis include redness in one or both eyes and itchiness in one or both eyes. Other common symptoms include blurred vision and sensitivity to light, a gritty feeling in one or both eyes, a discharge in one or both eyes that forms a crust during the night; and tearing.
• Uveitis: Symptoms include light sensitivity, blurring of vision, pain, and redness of the eye. Uveitis may come on suddenly with redness and pain, or it may be slow in onset with little pain or redness, but with gradual blurring of vision.
• Xerophthalmia (dry eye): Symptoms of dry eye range form mild irritation and foreign body sensation to severe discomfort with sensitivity to light.
• Keratitis: Keratitis usually makes the eyes very painful and watery, bloodshot, and sensitive to light. The condition is often accompanied by blurred or hazy vision. If the herpes simplex virus is the cause, the individual will notice a small white spot on the cornea.
• Corneal abrasion: A corneal abrasion should be suspected if the individual has sustained an injury to the eye. Some of the symptoms experienced may include: a sensation of a foreign body in the eye (this feeling sometimes develops a few hours later rather than immediately after the apparent injury); tearing of the eyes; blurred vision or distortion of vision; eye pain when exposed to a bright light; and spasm of the muscles surrounding the eye causing the individual to squint.
• Retinitis pigmentosa: Each individual with retinitis pigmentosa may experience symptoms differently, depending upon the severity and progression of the condition. Some individuals with retinitis pigmentosa experience a slow, very progressive loss of vision, while others lose their visual ability much more quickly and severely. Other common symptoms may include: difficulty seeing in poor light (such as at dusk or in a dimly lit area) or in the dark; a diminished visual field, either central vision (a condition called macular dystrophy) or peripheral vision (sometimes referred to as tunnel vision); difficulty reading print (with a loss of central vision); difficulty deciphering detailed images (with a loss of central vision); difficulty with stumbling or tripping over objects not seen; clumsiness (with a loss of peripheral vision); and glare. The symptoms of retinitis pigmentosa may resemble other eye diseases, such as glaucoma.

• A person who experiences eye symptoms should be checked by a doctor. However, some eye diseases cause few or no symptoms in their early stages, so the eyes should be checked regularly (every 1-2 years or more frequently if there is an eye condition). Healthcare professionals that deal with eye disorders include: opticians - they dispense glasses and do not diagnose eye problems and optometrists - they perform eye exams and may diagnose eye problems. Optometrists may prescribe glasses and contact lenses. In some states, they prescribe eye drops to treat diseases. Ophthalmologists are medical doctors who diagnose and treat diseases that affect the eyes. Ophthalmologists may also provide routine vision care services, such as prescribing glasses and contact lenses.
• An individual with eye or vision problems describes the location and duration of the symptoms, and then the doctor examines the eye, the area around it, and possibly other parts of the body, depending on the suspected cause. An eye examination usually includes refraction, a visual field testing, ophthalmoscopy, a slit lamp examination, and tonometry. A doctor may take a sample of eye secretions from the conjunctiva for laboratory analysis to determine which form of infection the individual has and how best to treat it. A doctor will ask about any eye pain or discomfort.
• Visual acuity test: Acuity refers to the sharpness of vision or how clearly the individual sees an object. In this test, the eye doctor checks to see how well the individual reads letters from across the room. The eyes are tested one at a time, while the other eye is covered. Using a chart (called a Snellen eye chart) with progressively smaller letters from top to bottom, an eye doctor determines if the individual has 20/20 vision or less acute vision.
• Slit-lamp examination: A slit-lamp allows the eye doctor to see the structures at the front of the eye under magnification. The microscope is called a slit lamp because it uses an intense line of light (or a slit) to illuminate the cornea, iris, lens, and the space between the iris and cornea. The slit allows the doctor to view these structures in small sections, which makes it easier to detect any small abnormalities.
• Retinal examination: In a retinal examination, an eye doctor puts dilating drops in the eyes to open the pupils wide and provide a bigger window to the back of the eyes. Using a slit lamp or a special device called an ophthalmoscope, the doctor can examine the lens for signs of a cataract, glaucoma, or damage to the retina. Dilating drops usually keep the pupils open for a few hours before their effect gradually wears off. Until then, the individual will probably have difficulty focusing on close objects, while distance vision is generally less affected. With the pupils open this wide, individuals may want sunglasses for their trip home, especially if it is a bright day. Also, it may be safer to let someone else do the driving.
• Genetic testing: Genetic testing is available for some genetic eye disorders. For example, genetic testing is available for several genetic mutations associated with retinitis pigmentosa, including: RLBP1, RP1, RHO, RDS, PRPF8, PRPF3, CRB1, ABCA4, and RPE65.

• Vision problems :
• Eyeglasses or contact lenses are the treatment for vision disturbances, such as astigmatism, hyperopia, and myopia.
• Lenses with bifocal or progressive addition lenses (PALs) are the most common correction for presbyopia. Bifocal means two points of focus: one section corrects for distant vision and the other section corrects for near vision. There are multifocal contact lenses available also for individuals with presbyopia.
• Progressive addition lenses are similar to bifocal lenses, but they offer a more gradual visual transition between the two prescriptions, with no visible lines between them.
• Reading glasses are another choice. Unlike bifocals and PALs, which most people wear all day, reading glasses are typically worn just during close work. If the individual wears contact lenses, an eye doctor can prescribe reading glasses that can be worn while the contacts are in. Reading glasses may be purchased over-the-counter (OTC) at a retail store or higher-quality versions are also available by prescription from an eye doctor.
• Because the human lens continues to change as an individual grows older, the presbyopic prescription will increase over time as well.
• Surgery: Surgical options to treat vision problems are available. LASIK, which stands for laser-assisted in situ keratomileusis, is one of the most popular modern treatments for a number of refractive errors, including myopia, hyperopia, and astigmatism. LASIK has a number of benefits; aside from the short amount of time required for the procedure itself, the LASIK procedure allows for rapid healing with minimal discomfort. Laser vision correction takes only about 15 minutes to complete. Most individuals see well enough to drive within 24 hours of their LASIK treatment.
• Although LASIK is an option for most individuals with vision problems, there are certain groups of people who are not good candidates for the surgery, including: those under the age of 21 as most individual's eyes are still developing when they are younger, and it is important that the prescription has stabilized before performing LASIK surgery to correct the vision; those with autoimmune conditions such as lupus, Sjogren's syndrome, and rheumatoid arthritis; those with scarred corneas or a history of herpes infection in the eye; and women who are pregnant or breastfeeding. Often, prescriptions will fluctuate dramatically during and after pregnancy. Women should wait until after they are done nursing before undergoing LASIK.
• First, the individual's prescription is entered into a computer that controls the laser. After the eye is prepared and numbed with anesthetic drops, the surgeon creates a flap in the cornea using an extraordinarily precise instrument called a microkeratome. The individual may feel some pressure during this portion of the procedure. The laser is then positioned over the eye, where it will emit small, controlled bursts of energy. Depending on the desired outcome of the surgery, small amounts of corneal tissue will be removed in order to change the focus of the eye. For the duration of the laser's operation, the surgeon will closely monitor the eye through a surgical microscope to make sure the desired prescription has been achieved. Next, the flap is returned to its original position. The flap will self-adhere and does not typically require sutures. The major advantages of corneal flap creation are that healing is faster and that discomfort is greatly reduced.
• It is recommended by healthcare professionals to go directly home and sleep (or at least keep the eyes closed) for about four hours. The eyelids will help the corneal flap to continue the bonding process. After this time period, it is essential that the individual keep their eyes lubricated with the drops provided the surgeon and follow all of the postoperative instructions.
• Photoreactive keratectomy (PRK): Photoreactive keratectomy (PRK) is similar to LASIK in that a laser is used to reshape the cornea to change the way that it focuses. However, in PRK, no flap is created in the cornea. Instead, a thin layer of epithelial, or surface, cells is removed to expose the corneal tissue underneath. PRK is effective for patients with myopia and astigmatism. PRK is an alternative for those who are not suitable candidates for LASIK, including those whose corneas are too thin to accommodate a flap.
• Because there is no corneal flap to protect the treated area, patients who undergo PRK can expect to experience more discomfort and a slightly longer recovery period than those who undergo LASIK. Surgeons will likely place a bandage contact lens on the affected eye to protect it during the first few days after surgery. Once the healing period is over, however, PRK patients should enjoy the same amount of success and satisfaction as with other procedures.
• Conjunctivitis :
• A doctor may prescribe antibiotic eyedrops, such as Neosporin®, if the infection is bacterial. The infection should clear within several days of starting treatment. Antibiotic eye ointment, in place of eyedrops, is sometimes prescribed for treating bacterial conjunctivitis in children. An ointment is often easier to administer to an infant or young child than are eyedrops. It is important to use the medication as prescribed to prevent recurrence of the infection.
• Viral conjunctivitis cannot be treated with antibiotic eyedrops or ointment. Like a common cold, individuals can use an over-the-counter (OTC) remedy, such as naphazoline (Vasoclear®, Naphcon®) to relieve some symptoms. Individuals may notice a worsening of symptoms in the first three to five days. Signs and symptoms should gradually clear on their own. It may take up to two to three weeks from the time of infection for the virus to go away.
• If the irritation is allergic conjunctivitis, a doctor may prescribe one of many different types of eyedrops. These may include antihistamines, decongestants, mast cell stabilizers, steroids, and anti-inflammatory drops.
• Xerophthalmia (Dry eye) :
• In treating dry eye, the first thing to do is to remove or reduce the cause. Reducing contact lens wear time and taking breaks from intense visual work are just two such examples. The use of over-the-counter (OTC) artificial teardrops is the primary treatment for dry eye. If the individual has chronic dry eye, it is important to use the drops even when the eyes feel fine, to keep them lubricated. If the eyes dry out while sleeping, there are thicker lubricants, such as ointments, which can be used at night.
• Temporary punctal occlusion: A temporary punctal occlusion is a procedure that closes the ducts that drain tears out of the eye. A plug that will dissolve quickly is inserted into the tear drain of the lower eyelid. This is a temporary procedure, done to determine whether permanent plugs can provide an adequate supply of tears.
• Permanent punctal occlusion: Permanent punctal occlusion is used if temporary plugging of the tear drains works well. Permanent punctal occlusion involves the use of silicone plugs placed in the tear ducts. The plugs will hold tears around the eyes as long as they are in place. They can be removed. Rarely, the plugs may come out spontaneously or migrate down the tear drain. Many individuals find that the plugs improve comfort and reduce the need for artificial tears.
• Restasis: Restasis® is a prescription eye drop used for the treatment of chronic dry eye. It helps the eyes increase their own tear production.
• Other medications: Other medications, including ophthalmic anti-inflammatory eye drops and eye ointments (steroids and non-steroids), may also be beneficial in some cases.
• Surgery: If needed, the ducts that drain tears into the nose can be permanently closed to allow more tears to remain around the eye. This is done with a local anesthetic on an outpatient basis. There are no limitations in activity after having this surgery.
• Uveitis :
• Treatment of uveitis depends in large part on what's causing the condition. Often, a doctor prescribes anti-inflammatory medications, such as ophthalmic corticosteroids or non-steroidal antiinflammatory drugs. A doctor also could give the corticosteroids by pill or by injection into the eye. If uveitis is caused by an infection, antibiotics, antiviral medications, or some other medicine may be given with or without corticosteroids to bring the infection under control. If uveitis is caused by an underlying condition, treatment will focus on treating that specific condition.
• The part of the eye affected by uveitis, either the front (anterior) or back (posterior) of the uvea, may determine the duration of the condition. With proper treatment, anterior uveitis can clear up in a matter of days to weeks. Posterior uveitis, on the other hand, may last several months or years and could permanently alter vision.
• If the uveitis responds poorly to corticosteroids or becomes severe enough to threaten vision, the individual may need to try a different kind of medication, such as an immunosuppressive or cytotoxic agent.
• Vitrectomy, surgery to remove the jelly-like material in the eye (vitreous), may sometimes be necessary for diagnosis and treatment of uveitis.
• Keratitis :
• Minor corneal infections such as keratitis are commonly treated with anti-bacterial or anti-fungal eye drops. If the problem is more severe, a person may receive more intensive prescription antibiotic treatment to eliminate the infection and may need to take steroid eye drops to reduce inflammation. With residual corneal scarring or thinning, corneal transplantation may be necessary to restore vision. Early treatment may help reduce the risk of complications. Frequent visits to an eye care professional may be necessary for several months to eliminate the problem.
• Retinitis pigmentosa :
• Effective treatments for retinitis pigmentosa are currently unknown. Retinal microchip implants have been investigated for treating blindness associated with retinitis pigmentosa. In early research, Artificial Silicon Retina (ASR) microchips in patients with retinitis pigmentosa have shown promising improvements in visual function. The ASR microchips measure 2mm in diameter and one-thousandth of an inch thick and contain approximately 5,000 microscopic solar cells that convert light into electrical impulses. These cells are intended to replace photoreceptors in the retina, which are damaged in patients with retinitis pigmentosa. Study results are variable and additional research is needed to better understand the role of retinal microchip implants in patients with retinitis pigmentosa.

A Strong scientific evidence

• Vitamin A : Vitamin A is a fat-soluble vitamin that is derived from two sources: preformed retinoids and provitamin carotenoids. Retinoids, such as retinal and retinoic acid, are found in animal sources such as livers, kidneys, eggs, and dairy produce. Carotenoids like beta-carotene (which has the highest vitamin A activity) are found in plants such as dark or yellow vegetables and carrots. Vitamin A deficiency can lead to various eye disorders including Bitot's spot, the buildup of keratin debris in the conjunctiva. Oral vitamin A is the treatment of choice for xerophthalmia (dry eye) due to prolonged vitamin A deficiency and should be given immediately once the disorder is established.
• Vitamin A toxicity, or hypervitaminosis A, is rare in the general population. Vitamin A toxicity can occur with excessive amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be acute or chronic. An infant with acute toxicity can develop a bulging fontalle (the soft spot on the head) and symptoms similar to a brain tumor. Adults experience less specific symptoms such as headache, dizziness, fatigue, malaise, blurry vision, bone pain and swelling, nausea, and/or vomiting. Severe toxicity can lead to eye damage, high levels of calcium, and liver damage. Persons with liver disease and high alcohol intake may be at risk for hepatotoxicity from vitamin A supplementation. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or cardiovascular disease.

B Good scientific evidence

• Iodine : Povidone-iodine solutions appear to have broad-spectrum activity against bacteria and have been used in the management of childhood bacterial conjunctivitis. Povidone-iodine solutions may also be used for ophthalmia neonatorum, a type of bacterial conjunctivitis with eye discharge that occurs during the first month of life, and may be as effective as other anti-bacterial solutions such as neomycin-polymyxin B-gramicidin. Medical supervision is recommended and povidone-iodine solutions are not an effective treatment for viral conjunctivitis. Prior to ophthalmologic procedures, povidone-iodine solutions are used for sterilization for ocular surgery infection prevention.
• Reactions can be severe and deaths have occurred with exposure to iodine. Avoid iodine-based products if allergic or hypersensitive to iodine. Do no use for more than 14 days. Avoid Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) with hyperkalemia (high amounts of potassium in the blood), pulmonary edema (fluid in the lungs), bronchitis, or tuberculosis. Use cautiously when applying to the skin because it may irritate/burn tissues. Use sodium iodide cautiously with kidney failure. Avoid sodium iodide with gastrointestinal obstruction. Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine for perianal preparation during delivery or postpartum antisepsis.
• Vitamin A : Retinitis pigmentosa is a genetic disorder that affects night vision. Early symptoms include night blindness and progressive loss of vision over time. Based on recent findings, vitamin A in the palmitate form has been recommended in patients with retinitis pigmentosa.
• Vitamin A toxicity, or hypervitaminosis A, is rare in the general population. Vitamin A toxicity can occur with excessive amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be acute or chronic. An infant with acute toxicity can develop a bulging fontalle (the soft spot on the head) and symptoms similar to a brain tumor. Adults experience less specific symptoms such as headache, dizziness, fatigue, malaise, blurry vision, bone pain and swelling, nausea, and/or vomiting. Severe toxicity can lead to eye damage, high levels of calcium, and liver damage. Persons with liver disease and high alcohol intake may be at risk for hepatotoxicity from vitamin A supplementation. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or cardiovascular disease.

C Unclear or conflicting scientific evidence

• Acupuncture : Acupuncture is a technique of inserting and manipulating needles into "acupuncture points" on the body with the aim of restoring health and well-being, e.g. treating pain and diseases.The practice of acupuncture originated in China 5,000 years ago. Today, it is widely used throughout the world and is one of the main pillars of Chinese medicine. Although a few clinical studies support the use of acupuncture for keratoconjunctivitis sicca (dry eyes), there is insufficient evidence for a clear understanding of the benefits of acupuncture for this disorder.
• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, medical conditions of unknown origins, or infections. Acupuncture should not be applied to the chest in patients with lung diseases or on any area that may rely on muscle tone to provide stability. Avoid use in patients with needle phobias. Use cautiously with bleeding disorders, neurological disorders, seizure disorders, or diabetes. Use cautiously in elderly or medically compromised patients. Use cautiously in patients who will drive or operate heavy machinery after acupuncture. Use cautiously if taking anticoagulants.
• Chelation therapy : EDTA chelation became well known during the 1950s when it was proposed as a method to cleanse the blood and blood vessel walls of toxins and minerals. The technique involves infusing a chemical called ethylene diamine tetraacetic acid (EDTA) into the blood. The therapy is sometimes given by mouth and occasionally other chemicals may be used. EDTA is commonly used in ophthalmology as a calcium-binding agent in calcific band keratopathy. However, there is a lack of available evidence for this use. More studies are needed.
• Chelation may be dangerous in people with heart, kidney, or liver disease or with conditions affecting blood cells or the immune system. Use during pregnancy, breastfeeding, or in children may also be dangerous due to potential toxic effects. Serious side effects have been associated with chelation therapy, such as dangerously low calcium blood levels, damage to bone marrow, which decreases the ability to make new blood cells, kidney damage (with elevated creatinine levels), very low blood pressure, fast heart rate, increased risk of bleeding or blood clots (including interference with the effects of the blood thinning drug warfarin [Coumadin®]), bacterial blood infections, seizures, allergic or immune system reactions, heart rhythm abnormalities, and unstable blood sugars. Other side effects may include fever, nausea, vomiting, gastrointestinal upset, excessive thirst, sweating (diaphoresis), headache, decreased thyroid function, fatigue, low white blood cell count (leukopenia), or low blood platelet count (thrombocytopenia). Severe reactions have occurred in which people have stopped breathing. Although deaths have been reported in people receiving chelation, it is not clear that chelation therapy was the direct cause.
• Chiropractic : Chiropractic is a healthcare discipline that focuses on the relationship between musculoskeletal structure (primarily the spine) and body function (as coordinated by the nervous system), and how this relationship affects the preservation and restoration of health. The broad term "spinal manipulative therapy" incorporates all types of manual techniques, including chiropractic. There are several published articles with positive findings from case series and case reports suggesting that chiropractic manipulation may be of benefit for vision problems from diverse origins. However, randomized controlled trials are currently lacking. There is also not enough reliable scientific evidence to conclude the effects of chiropractic techniques for the recovery or prevention of visual field loss.
• Avoid with vertebrobasilar vascular insufficiency, aneurysms, arteritis, or unstable spondylolisthesis. Avoid use on post-surgical areas of para-spinal tissue. Use cautiously with acute arthritis, brittle bone disease, conditions that cause decreased bone mineralization, bleeding disorders, migraines, or if at risk of tumors or metastasis of the spine. Use extra caution during cervical adjustments. Avoid if pregnant or breastfeeding due to a lack of scientific data.
• Chondroitin : Chondroitin was first extracted and purified in the 1960s. It is currently manufactured from natural sources (shark/beef cartilage or bovine trachea) or by synthetic means. Chondroitin is sometimes used as a component of eye solutions used for keratoconjunctivitis, corneal preservation, and intraocular pressure. These solutions should only be used under the supervision of an ophthalmologist. Additional study is needed to better determine the effectiveness and safety of chondroitin for ophthalmologic uses.
• Use cautiously if allergic or hypersensitive to chondroitin sulfate products. Use cautiously in patients with shellfish allergy, due to the possibility of allergic reaction. Hives, rash, sun skin sensitivity, and worsening of previously well-controlled asthma have been reported. Use cautiously with bleeding disorders and with blood-thinners like warfarin (like Coumadin®). Avoid with prostate cancer or increased risk of prostate cancer. Avoid if pregnant or breastfeeding.
• Echinacea : Oral Echinacea purpurea may offer some benefits in people with low-grade uveitis. Further research is needed to confirm preliminary research findings.
• Avoid if allergic to echinacea, its constituents, or any members of the Asteraceae/Compositae family (ragweed, chrysanthemums, marigolds, daisies). Use cautiously in patients prone to atopic reactions and in those with hemochromatosis and diabetes. Some natural medicine experts discourage the use of echinacea by people with conditions affecting the immune system, such as HIV/AIDS, some types of cancer, multiple sclerosis, tuberculosis, and rheumatologic diseases (such as rheumatoid arthritis or lupus). Use parenteral preparations of echinacea (no longer approved for use in Germany) cautiously. Use tinctures cautiously with alcoholic patients or in patients taking disulfiram or metronidazole. Avoid using echinacea in patients presenting for anesthesia. Use cautiously if pregnant or breastfeeding.
• Eyebright : In Europe, the herb eyebright (Euphrasia officinalis) has been used for centuries as a rinse, compress, or bath against eye infections and other eye-related irritations (a use reflected in many of its vernacular names). When taken by mouth, eyebright has been used to treat inflammation of nasal mucous membranes and sinusitis. Eyebright has been used in ophthalmic (eye) solutions for centuries, in the management of multiple eye conditions. Currently, there is insufficient available scientific evidence for or against the use of eyebright in the treatment of conjunctivitis.
• Avoid in individuals with a known allergy or hypersensitivity to eyebright. Hypersensitivity to members of the Scrophulariaceae family may lead to a cross-sensitivity reaction. Use cautiously as an eye treatment, particularly homemade preparations, due to the risk of infection if not sterile. Use cautiously with diabetes and drugs that are broken down by the liver. Avoid if pregnant or breastfeeding.
• Flaxseed and flaxseed oil : Taking flaxseed oil capsules by mouth may reduce keratoconjunctivitis sicca (dry eye) associated with Sjogren's syndrome patients.
• Flaxseed has been well-tolerated in studies for up to four months. Avoid if allergic to flaxseed, flaxseed oil or other plants of the Linaceae family. Avoid large amounts of flaxseed by mouth and mix with plenty of water or liquid. Avoid flaxseed (not flaxseed oil) with a history of esophageal stricture, ileus, gastrointestinal stricture or bowel obstruction. Avoid with a history of acute or chronic diarrhea, irritable bowel syndrome, diverticulitis or inflammatory bowel disease. Avoid topical flaxseed in open wounds or abraded skin surfaces. Use cautiously with history of a bleeding disorder or with drugs that cause bleeding risk (like anticoagulants and non-steroidal anti-inflammatories (like aspirin, warfarin, Advil®)), high triglyceride levels, diabetes, mania, seizures or asthma. Avoid if pregnant or breastfeeding. Avoid with prostate cancer, breast cancer, uterine cancer, or endometriosis. Avoid ingestion of immature flaxseed pods.
• Grape seed : Several small studies suggest that grape seed (Vitis vinifera) may slow the progression of retinopathy (damage to the retina caused by diabetes or high blood pressure). Visual performance may be improved in healthy patients as well. Further research is needed to better determine the effectiveness of grape seed for vision problems.
• There are reports of people with allergy to grapes or other grape compounds, including anaphylaxis. Individuals allergic to grapes should not take grape seed and related products. Use cautiously if taking anticoagulants. Use cautiously with blood pressure disorders or if taking ACE inhibitors. Grape seed may interfere with the way the body processes certain drugs that use the liver's cytochrome P450 enzyme system. Avoid if pregnant or breastfeeding.
• Kinetin : Kinetin is a chemical analogue of cytokinins, a class of plant hormones that promotes cell division. Kinetin is found in both plants and animals. Kinetin may be effective for decreasing ocular blood pressure, although currently there is insufficient available evidence to make a strong conclusion. More research is needed in this area.
• Avoid if allergic or hypersensitive to kinetin. Use cautiously with coagulation or hematologic (blood) disorders or if taking anticoagulants or antiplatelets (blood thinners). Avoid if pregnant or breastfeeding.
• Lutein : Lutein and zeaxanthin are found in high levels in foods such as green vegetables, egg yolk, kiwi fruit, grapes, orange juice, zucchini, squash, and corn. For some commercially available supplements, lutein is extracted from marigold petals. Spinach and collard greens, both rich in lutein, are associated with a reduced risk for age-related macular degeneration. However, preliminary evidence does not support a link between levels of lutein in the body and reduced risk for lens opacities. More research is required.
• Avoid in individuals with a known allergy or hypersensitivity to lutein or zeaxanthin. Use cautiously if at risk for cardiovascular disease or cancer. Avoid if pregnant or breastfeeding.
• Propolis : Propolis is a natural resin created by bees, used in the construction of hives. Propolis is produced from the buds of conifer and poplar tress, in combination with beeswax and other bee secretions. Laboratory studies suggest anti-viral and anti-inflammatory activity of propolis. There is limited poor-quality study of propolis for the treatment of corneal complications of varicella zoster, reporting faster healing and improvement of sight. Better human research is needed.
• Patients who have had an allergic/hypersensitivity reaction to propolis, Populus nigra L. (black poplar), poplar bud, bee stings/bee products (including honey), or Balsam of Peru should avoid propolis. There are multiple reports of swelling, fluid collection, redness, burning, eczema, swelling, fever, and other allergic reactions with the repeated use of propolis on the skin. Use cautiously with asthma or gastrointestinal disorders. Avoid if pregnant or breastfeeding because of the high alcohol content in some products.
• Rose hips : Rose hips are the fruits that develop from the blossoms of the wild rose (Rosa spp.). They are typically orange to red in color, but some species may be purple or black. Preliminary evidence suggests that an herbal formula (Ophthcare®) containing rose hips may help treat a variety of ophthalmologic disorders. Additional study is needed to determine if rose hips are an effective treatment for these indications.
• Avoid in individuals with a known allergy/hypersensitivity to Rosa spp., rose hip dust, its constituents, or members of the Rosaceae family.
• Selenium : Although selenium appears to be involved in cataract development and uveitis (eye inflammation), it is not known whether selenium supplements may affect the risk of developing these eye disorders. Additional research in this area is warranted.
• Avoid with history of nonmelanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
• Spirulina : Blue-green algae may help treat blepharospasm (eyelid twitch or spasm) but additional high-quality research is necessary to make a recommendation.
• Avoid if allergic or hypersensitive to spirulina or blue-green algae. Use cautiously with phenylketonuria (a genetic disorder of a liver enzyme that disrupts normal body functions), autoimmune diseases, bleeding disorders, diabetes, and osteoporosis. Use cautiously with products containing the blue-green algae species Anabaena spp., Aphanizomenon spp., and Microcystis spp.; in underweight patients or in those taking antiobesity agents or appetite suppressants; and if consuming a high-protein diet. Avoid in children and if pregnant or breastfeeding.
• Taurine : Taurine, or 2-aminoethanesulfonic acid, was originally discovered in ox (Bos taurus) bile and was named after taurus or bull. A nonessential amino acid-like compound, taurine, is found in high abundance in the tissues of many animals, especially sea animals, and in much lower concentrations in plants, fungi, and some bacteria. Taurine supplementation may reduce visual fatigue due to visual display terminals. More search is needed to make a conclusion.
• Taurine is an amino acid and it is unlikely that there are allergies related to this constituent. However, allergies may occur from multi-ingredient products that contain taurine. Use cautiously in patients with high cholesterol, low blood pressure, coagulation disorders, potential for mania, or epilepsy. Avoid exercise or alcohol after consumption of energy drinks containing taurine, caffeine, glucuronolactone, B vitamins, and other ingredients. Use cautiously if pregnant or breastfeeding because taurine is a natural component of breast milk.
• Tea tree oil : Early studies found that tea tree oil may be an effective treatment for ocular demodex (parasitic mites). Large, well-designed clinical trials are needed before a strong recommendation can be made.
• Avoid if allergic or hypersensitive to tea tree oil (Melaleuca alternifolia), any of its constituents, balsam of Peru, benzoin, colophony (rosin) tinctures, eucalyptol, or members of the Myrtle (Myrtaceae) family. Avoid taking tea tree oil by mouth. Avoid if taking antineoplastic agents. Use tea tree oil applied to the skin cautiously in patients with previous tea tree oil use. Avoid if pregnant or breastfeeding.
• Thymus extract : Thymus extracts for nutritional supplements are usually derived from young calves (bovine). Bovine thymus extracts are found in capsules and tablets as a dietary supplement. Preliminary evidence suggests that thymus extract, in addition to local treatment, reduces the recurrence rate of keratitis. Further well-designed clinical trials are still required.
• Avoid in individuals with a known allergy or hypersensitivity to thymus extracts. A severe anaphylactic reaction to injected thymostimulin has been documented in a case report. Allergy to thymic extracts has not been demonstrated in currently available clinical trials. Use bovine thymus extract supplements cautiously due to potential for exposure to the virus that causes "mad cow disease." Avoid use with an organ transplant or other forms of allografts or xenografts. Avoid if receiving immunosuppressive therapy, with thymic tumors, myasthenia gravis (neuromuscular disorder), untreated hypothyroidism, or if taking hormonal therapy. Avoid if pregnant or breastfeeding; thymic extract increases human sperm motility and progression.
• Turmeric : Poorly designed human study suggests a possible benefit of curcumin (from Curcuma longa) in the treatment of uveitis (eye inflammation). Reliable human research is necessary before a firm conclusion can be drawn.
• Allergic reactions to turmeric may occur, including contact dermatitis (an itchy rash) after skin or scalp exposure. People with allergies to plants in the Curcuma genus are more likely to have an allergic reaction to turmeric. Use cautiously in patients allergic to turmeric or any of its constituents (including curcumin), to yellow food colorings, or to plants in the Zingiberaceae (ginger) family. Turmeric may also increase bleeding in sensitive individuals, including those taking blood thinning medications such as aspirin and warfarin (Coumadin®). Avoid in medicinal amounts if pregnant or breastfeeding. Turmeric should be stopped prior to scheduled surgery.
• Vitamin A : High-dose vitamin A supplementation in addition to vitamin E has been suggested to help improve ocular healing after photoreactive keratectomy, a type of laser eye surgery used to correct nearsightedness, and to improve visual acuity. Additional evidence is necessary before a definitive conclusion can be reached.
• Vitamin A toxicity, or hypervitaminosis A, is rare in the general population. Vitamin A toxicity can occur with excessive amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be acute or chronic. An infant with acute toxicity can develop a bulging fontalle (the soft spot on the head) and symptoms similar to a brain tumor. Adults experience less specific symptoms such as headache, dizziness, fatigue, malaise, blurry vision, bone pain and swelling, nausea, and/or vomiting. Severe toxicity can lead to eye damage, high levels of calcium, and liver damage. Persons with liver disease and high alcohol intake may be at risk for hepatotoxicity from vitamin A supplementation. Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or cardiovascular disease.
• Vitamin E : Vitamin E is a fat-soluble vitamin with antioxidant properties. High-dose vitamin E plus vitamin A (taken by mouth) may improve healing after photorefractive keratectomy. Additional research is necessary before this use of vitamin E can be concluded as being safe or effective. Four-month oral supplementation with vitamin E had no apparent effect on uveitis-associated macular edema or visual acuity in limited available study. High quality clinical research is needed.
• Vitamin E may increase bleeding in sensitive individuals, including those taking blood thinning medications, such as aspirin and warfarin (Coumadin®). Avoid if allergic or hypersensitive to vitamin E. Avoid with retinitis pigmentosa (loss of peripheral vision). Avoid above the recommended daily level in pregnant women and breastfeeding women.

D Fair negative scientific evidence

• Vitamin E : Oral vitamin E does not appear to slow visual decline in people with retinitis pigmentosa and may be associated with more rapid loss of visual acuity, although the validity of this finding has been questioned. Until further evidence is available, vitamin E may not be advisable in this condition. Therapy decisions should be under medical supervision.
• Strong negative scientific evidence :
• Vitamin B12 : Vitamin B12 is an essential water soluble vitamin that is commonly found in a variety of foods such as fish, shellfish, meats, and dairy products. Vitamin B12 is frequently used in combination with other B vitamins in a vitamin B complex formulation. Vitamin B12 can cause severe and swift optic atrophy and is contraindicated in early Leber's disease (hereditary optic nerve atrophy).