As an optometrist, I am constantly amused by the beliefs that my patients hold about their vision. I’ve realized that there are many misconceptions that the general public has about their eyes and the visual system, so I am going to address the top five here:
Myth #1: You don’t need eyeglasses if your vision is not blurry.
Truth: While it is true that most people who wear prescription lenses have blurred vision, that is not the only reason that doctors prescribe glasses. Lenses are commonly used in vision therapy to train the eye muscles to work together. Special lenses are used to improve performance in specific sports like golf or tennis. Lenses are used to prevent eyestrain from prolonged computer use. They can also be used to eliminate glare which in turn enhances the clarity of the images that you see. Lenses are used to enhance color discrimination in persons who are red-green colorblind. Lenses are often prescribed to disguise cosmetic disfigurements caused from accidents or to completely change a person’s eye color. There are many reasons that lenses may be prescribed, and they have nothing to do with the blurriness of your vision.
Myth #2: Wearing glasses will make your eyesight weaker.
Truth: For those who do wear glasses, it may seem that over time your eyesight becomes weaker, or you become dependent upon the lenses. In reality what happens is your brain becomes accustomed to seeing clearly. When we are born, we aren’t aware that our vision is poor. We only know what we see, and so we interpret that vision as “normal”. Once we are prescribed glasses, the images that were once blurry are now clear to us, and many of us start realizing what we were missing. More importantly, our brain now sees these images clearly. Once we remove our glasses, the brain sees a blurred picture, and since it now knows that things should be clearer, it revolts and demands that you put the glasses back on. Aren’t our brains smart?!
Myth #3: You will “spoil” your eyes by reading in poor light.
Truth: You cannot make your eyes worse by reading in bad lighting. What you will do is create a situation where you get frustrated because you can’t see clearly. When you read, three things happen: your outer eye muscles move the eyes inward (converge), your pupils get smaller (constrict), and the inner focusing muscles are activated and signal to the lens to change focus (accommodate). These three things always occur together when we move something closer to us. In bright light, the pupil will reflexively constrict and this stimulates the accommodative system. A smaller pupil also blocks out stray rays of light and creates a better depth of focus. Conversely, in dim light the pupils get larger (dilate) to let in more light. The more stray light entering the eye results in glare and poorer depth of focus. The accommodative system is not stimulated so the result is poor vision.
Does this weaken your eyes?
No. Once you turn a bright light on, you’ll notice that the vision automatically improves. So the solution? Use a bright light when you are reading at night.
Myth #4: Eating lots of carrots will improve your vision.
Truth: Carrots contain beta-carotene, an important antioxidant that helps to fight free radical damage to the eye. Spinach, however, is packed with may more nutrients that are essential to eye health. Spinach, like carrots, contains beta-carotene. Spinach also contains lutein and zeaxanthin, two nutrients that are specific to the pigments that are contained in the retina, the tissue covering the back of the eye. Lutein and zeaxanthin have been shown in studies to lower the risk of age-related macula degeneration and cataracts. Other nutrients contained in spinach include Vitamin A, Vitamin C, Zinc and essential omega-3 fatty acids. These have all been found to reduce age-related eye diseases. Now I’m not saying that you should stop eating carrots; just add spinach to your diet as well.
Myth #5: You don’t need to have an eye exam if your vision is good.
Truth: Most people feel that they only need to get an eye exam when they experience a decrease in the clarity of their vision. They feel that if they can see, then nothing is wrong with their eyes. Nothing could be further from the truth! There are many eye diseases that manifest without any symptoms and could be well advanced before any loss of vision is experienced. Glaucoma is often referred to as the “thief of sight” because by the time most people are diagnosed, they have already experienced significant damage to the optic nerve and their peripheral (side) vision. Other examples are macula degeneration which results in significant reduction of your central vision, and diseases of the retina caused by diabetes or high blood pressure which cause leaking and bleeding of the delicate blood vessels in the eye. This leads to scarring and eventually vision loss. Once vision is lost, it cannot be regained. It is extremely important to have a complete eye examination at least once every few years by an eye-care professional. Make sure this examination includes a dilated fundus exam, where drops are placed in the eye to open the pupil. This allows the doctor to get a detailed view of the structures inside the eye and determine if there are any issues that need to be followed more carefully.
The old adage rings true here: “an ounce of protection is worth more than a pound of cure!”
Isn’t your vision worth it?
What are some of the interesting things that you have heard about the eyes that may be a myth? Leave a comment below, and I’ll address them in another post!