Go Ahead, Read in the Dark : Misconceptions About Eye Care Laid to Rest
A concerned mother dragged her young son into the ophthalmologist’s office, begging the doctor to talk some sense into the boy, whose reckless habits she was certain would drive him blind.
“The mother was frantic,” recalled Dr. Marshall Parks, a pediatric ophthalmologist at Children’s Hospital National Medical Center in Washington. “She said, ‘I want you to tell my son once and for all he can’t read in his bed under the covers with a flashlight. It’ll ruin his eyes.”’
Parks, who is also clinical professor of ophthalmology at George Washington University, looked at the boy seriously.
“Son,” he said, “you can read under the covers all you want. I used to read in the dark all the time--and still do.”
The human visual system, more complex than the most sophisticated camera, can be used under almost any condition without being damaged, Parks and other eye experts said in interviews.
“There is hardly anything in the environment or life style that plays any significant role in visual development,” said Dr. Robert Reinecke, professor and chairman of the ophthalmology department at Jefferson Medical College in Philadelphia.
The approximately 120 million Americans with normal, healthy eyes who need no corrective lenses to see well owe their good visual fortune almost entirely to their genetic makeup, doctors said.
Sight can be impaired by disease, injury and certain conditions--if they remain untreated--but the eye experts interviewed agreed that healthy people with good vision can do very little to improve or maintain their sight.
“There is no extra care or procedure that will make your eyes better,” said Dr. Wayne Fung, clinical ophthalmologist at Pacific Medical Center in San Francisco.
Fung cited seven commonly held misconceptions:
--Eyewashes keep eyes healthy. “This is not only unnecessary but can be harmful,” he said.
--Eyes are strengthened with exercises, such as rolling them around or doing “push-ups” with them by moving a pencil towards and away from the eyes. “This is completely unnecessary,” Fung said.
--Vision is improved by eating foods rich in Vitamin A, such as carrots. “Although a proper diet is necessary for good health, there is no evidence that flooding the body with Vitamin A makes the eyes stronger,” Fung said.
--People should read only under bright lights. “In fact, any light that is comfortable to the person--so long as it does not produce a glare on the page--is fine for the eyes. Remember, the eye is a perfect camera created by nature,” he said.
--Eye drops help maintain visual health. “Most drops will shrink the blood vessels in the white part of the eye, creating a more cosmetically appealing appearance in those with red eyes, but they do nothing for eye health,” Fung said. “Redness in the eyes is a reaction to something in the environment: wind, draft, dust, glare, smog, physical insult, lack of sleep. The drops can reverse the reddening effect temporarily, but if used repeatedly can actually be harmful.”
--Eyeglasses or contact lenses strenghten the eyes. “They help the patient see more accurately by physically bending light, helping the eyes focus more accurately. They are not like a cast on a broken leg or weights on someone trying to build muscles. They have no strengthening effect at all,” he said.
--Contact lenses can permanently correct nearsightedness, which afflicts 20 million Americans. “Myopic people discover after wearing contacts for a time their vision is normal even after removal of the contacts. That’s because the contact lenses flatten the front curvature of the cornea, or the window of the eye, making the eye less myopic. But this is not a permanent change, and the memory within the cornea will restore the previous curvature if the contacts are left off for prolonged periods,” he said.
For people with normal vision and no family history of such serious eye disorders as glaucoma or retinal detachments, the San Francisco-based American Academy of Ophthalmology--the largest group within the eye care profession--recommends only “occasional” eye exams between puberty and age 40.
People suffering from diabetes, severe high blood pressure or other diseases that could affect their vision, those who have a family history of serious eye disorders, or who show certain visual symptoms should be tested at least once every two years, said Academy President Dr. Bruce Spivey.
An eye specialist should be contacted immediately if any of the following symptoms appear:
--Blurry vision uncorrectable by lenses.
--Dimming of vision that comes and goes or sudden loss of vision.
--Loss of side vision.
--Crossed, turned or wandering eye.
--Twitching or shaking eye.
--Flashes or streaks of light.
--New floaters (spots, strings or shadows).
--Discharge, crusting or excessive tearing.
--Swelling of any part of the eye.
--Bulging of one or both eyes.
--Difference in the size of the eyes.
The academy recommends that high-risk infants, including those with a family history of infantile cataracts, glaucoma and genetic diseases, have a thorough eye examination.
All children should be screened by age 3 or 4 for a variety of disorders that can easily be corrected if caught early enough, but can impair vision if left untreated by the time the visual system matures around age 9.
“Children don’t know any better and may accept they way they see as normal, whether they see poorly with one eye or both eyes,” Parks said. “We urge parents to be alert for any sign of problems, including an eye that deviates, a child who does not recognize things at a distance, a child who squints when trying to see things that are far away.”
Therapies with glasses, eye patches, eye drops or surgery have produced “excellent results” when undertaken by 4 years of age, Parks said.
“Later, after age 7 or 8, it becomes virtually impossible to have permanent improvement in vision.”
Some common correctable childhoood problems include strabismus, or misaligned eyes; amblyopia, decreased vision in one eye caused by disuse; crossed eyes, and conditions such as astigmatism, the unequal curvature of the front of the eye.
Without early therapy, these conditions can irreversibly impair vision.