Vision Myths
Does reading in low light harm eyesight?
No. For centuries, candlelight illuminated words and images for readers. Sewing was performed by lamplight. Good lighting does prevent eye fatigue but poor lighting is not harmful.
Is reading fine print or tasks involving intricate detail work harmful to eyesight?
Sharp, clear images on the retina are not dependent upon muscles that can become fatigued. A camera does not “wear out” unusually fast because it takes photographs of details of small objects. Extended periods of visual concentration on fine print and intricate details may, however, lead to eyestrain and fatigue but it will not harm eyesight.
Does looking at a computer all day harm eyesight?
No. However, concentrating on screens of words and images causes you to blink less frequently and that reduces lubrication and that may well cause eyestrain and fatigue.
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What can I do to prevent eye fatigue?
Take regular breaks. Look up and across the room focusing on a distant object. Use artificial tears. Place your computer monitor 18 – 24 inches from your eyes, positioned at a very slight downward angle. If your vision blurs or your eyes tire easily, an examination by an ophthalmologist is recommended.
Is sitting close to a television screen harmful to eyesight?
No. Children can focus on close objects better than adults. There is no evidence that this behavior damages their eyesight. The habit of sitting “too close” to a television screen wanes over time. A person with nearsightedness may sit close for maximum image clarity. If a child must sit close to a screen to see clear images, an eye examination is recommended.
Are learning disabilities caused by eye problems?
Children with visually related learning disabilities such as dyslexia and dyscalcula have neural problems as opposed to eye problems. There is no significant evidence that eye problems cause learning disabilities. However, vision problems such as nearsightedness, farsightedness and astigmatism can directly affect a child’s reading ability, which, depending upon its severity, may well affect learning progress. Because of this, every child should have an eye examination to ensure all visual images are clear.
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Do children outgrow crossed eyes, misaligned eyes or lazy eyes?
No. Crossed eyes are not “outgrown”. Children with misaligned eyes may develop poor vision in one of their eyes because the brain will ignore a less than perfect image from one eye if there is a perfect image produced by the other eye. The eye producing the ignored image will not produce good images unless it is forced to do so. This is usually accomplished by placing a patch over the stronger eye. Children who appear to have misaligned eyes should be examined by an ophthalmologist. The earlier misaligned eyes are diagnosed, the sooner treatment can begin. Successful treatments include glasses, patches, prescription medicine and surgery.
Do only old people get cataracts?
No. Cataracts are a condition marked by a cloudy lens that affects the clarity of visual images on the retina. Proteins in the lens tissue decompose over time making aging the most common cause of cataracts but cataracts also occur as a result of trauma, diabetes, steroid use and previous eye surgery.
Do cataracts spread from one eye to the other eye?
No. In age related cataracts, the clouding effect is directly related to the development and clumping of decomposing proteins in the lens tissue of a specific eye. This process can be different in each lens of each eye so the cataracts may develop sooner in one eye, later in the other. Most age related cataracts develop gradually over a number of years.
If a cataract is the result of trauma, only the affected eye will have a cataract. Cataract formation from diabetes or steroid use is usually found in the lenses of both eyes as they are with age related cataract development.
Can eyes be transplanted?
The eye transmits images to the brain via the optic nerve. This cranial nerve contains more than a million nerve fibers that, if severed, cannot be reconnected. This is why, even during the most complicated optic surgery, the eye is never removed from its socket.
Corneas have been successfully transplanted for many years. Lenses are routinely replaced. Until neural ophthalmic researchers can successfully fuse millions of optic nerve fibers or produce an artificial optic nerve, whole eye transplants will remain impossible at this time.
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Can marijuana prevent glaucoma? How does smoking marijuana help glaucoma patients?
Glaucoma is a disease resulting from optic nerve damage. Abnormally high intra-ocular pressure frequently causes the optic nerve damage associated with glaucoma. Medical research has shown that a prominent chemical in marijuana – cannabinoid - reduces intra-ocular pressure in patients with primary open angle glaucoma but no more so than glaucoma medications currently available. Smoking anything places lungs at high risk for pulmonary diseases like emphysema and cancer. Cannabinoids in marijuana have yet to be successfully produced as eyedrops and even when cannabinoids are administered orally or intravenously, the intraocular pressure reduction is brief so the drug must be taken 8 – 10 times daily to control ocular pressure over a 24 hour period.
In light of these conclusions, coupled with the adverse side effects of marijuana as reported by the National Institute of Health, the National Eye Institute and The American Academy of Ophthalmology do not approve of marijuana in any form as an alternative treatment for increased intraocular pressure.
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