Seeing Is Believing
By Judd McNaughton, M.D., Greater Springfield LIVING WELL Magazine
Myths are everywhere. There are even entire television shows dedicated to testing and debunking them. Many myths have a bit of truth at their core, while others are completely baseless. Ophthalmology is no different. Here are a few myths we have encountered over the years and the truth behind them.
Myth #1: Reading in low light will damage your eyes.
Young Abraham Lincoln is famous for spending many hours by the evening fire reading any book he could find, yet many parents have heard that their children will damage their eyes if they read by dim light. While reading in low light for extended periods of time can cause fatigue and frustration, the eye was designed to function at a wide variety of light levels. In dim conditions, the pupil dilates to allow more light into the eye, while rod photoreceptors in the back of the eye detect the low levels of light.
So, children who stay up too late reading with dim light may be tired the next day due to lack of sleep, but they are not damaging their eyes.
Myth #2: Eating carrots and spinach will make you see better.
There is no question that a diet rich in vegetables will lead to greater health, so mom was right when she told you to eat them. Carrots are a source of vitamin A (beta-carotene) which is necessary in small amounts for your eyes to function. In countries with very poor dietary nutrition, vitamin A deficiency can cause eye disease. However, in the U.S. that is rarely a problem because nearly everyone gets adequate vitamin A for their eyes to function. Likewise eating green leafy vegetables, such as spinach, will not make you see better, but they do contain vitamins that play a role in preventing macular degeneration. So, be sure to eat your vegetables, but do not expect them to give you super vision or allow you to throw away your glasses.
Myth #3: Wearing (or not) glasses will make your eyes weak.
There are numerous myths regarding the wearing of glasses. Some people resist wearing glasses because they do not want to become too dependent upon them. Others are afraid that if they do not wear their glasses, they will damage their eyes. Some have heard that wearing sunglasses indoors is unhealthy. Still others have been warned that if they wear someone else’s glasses, it will harm their vision. For adults, none of these are true. Appropriately prescribed glasses simply help you see more clearly while you wear them. Wearing them does not make your eyes healthier, and avoiding them does not prevent your need for them. Wearing sunglasses indoors will certainly make things darker, but as discussed above regarding reading in dim light, the eyes are designed to see in a wide range of lighting conditions, and no harm will come of it. Wearing another person’s glasses is likely to cause eye strain and frustration unless your prescriptions are very similar, but no damage will occur. There is an exception to this rule. Children should not wear other people’s glasses for any extended period of time because their brains need to have a clear image from both eyes to learn to process vision correctly.
Myth #4: Using your eyes too much will wear them out.
Some people have the idea that eyes are like tires with a certain amount of tread. They try not to use their eyes too much so they won’t “run out of tread” during their lifetime. This myth may originate from the fact that prolonged reading and computer work can cause eyes to become fatigued from prolonged focusing. They can also become dry during those activities from the tear film evaporating as the blink rate naturally decreases with concentration. While taking breaks from prolonged near work can make those tasks more pleasant, the truth is that the eyes were well designed to be used near or at a distance, in bright or dim light, and for as many hours as are comfortable.
Myth #5: Eye transplants are now available.
While cornea (clear layer on the front of the eye) transplants have been very successfully performed for over 100 years, eye transplants are still firmly planted in the realm of science fiction. The inability to get nerve tissue to transplant is the primary limiting factor. For the same reasons, the eyeball is never removed from the socket during eye surgery (unless it is being removed permanently) since there would be no way to successfully reattach the nerve tissue if this were done.
Myth #6: If you are seeing well, then there is nothing wrong with your eyes.
While most of these myths are fairly benign in nature, this is one myth that can cause serious harm. While it is true that poor vision is a red flag that something may be wrong, the converse is not necessarily true. Some diseases can cause serious damage before you notice them. For instance, glaucoma causes optic nerve damage over time and eventually can cause permanent peripheral vision loss. While it can be detected during a routine eye exam, if an individual waits until they notice visual changes on their own, a significant amount of nerve damage may already be done. By this time, the vision loss is permanent, and it can be a struggle to maintain the peripheral vision that remains. For this reason, we recommend that if you are over 60 years of age, have a significant history of eye problems, or a strong family history of eye problems, you should have your eyes checked every year by your ophthalmologist. For those under the age of 60 with no history of eye problems, an ophthalmic exam every one to two years is appropriate. Regardless of your age or vision status, caring for your eyes is always worth the effort.
C. Byron Faulkner, M.D., and Judd McNaughton, M.D., are board certified comprehensive ophthalmologists with Eye Surgeons of Springfield, Inc. They can help you separate fact from fiction and answer your ophthalmic questions. They provide comprehensive eye care and have a full-service optical shop on location. They are located at 1330 E. Kingsley Street, Springfield, MO 65804 and can be reached at 417- 887-1965 or 800-822-2553.
