The phrase “eat your carrots; they’re good for your eyes!” is a staple part of many childhoods. This is part of a larger truth–diets rich with fruits and vegetables are important for keeping your eyes healthy. Research shows there are benefits to eating dark leafy greens (like kale, collard greens, and spinach) and foods high in omega-3 fatty acids (like salmon and tuna). This blog will focus on understanding how the eye works, different common eye conditions and diseases, and resources to promote healthy vision.
The National Eye Institute’s (NEI) NEI for Kids page offers an excellent simplified explanation of how the eye works: first, rays of light bounce off the object and enter the eye through the clear cornea, which helps focus the light before it travels through the pupil. An eye’s irises–the colored part surrounding the black pupil–control the dilation of the pupil and therefore how much light enters the eye. The light then reaches the lens before it is focused and hits the back of the eye. Therein lies the retina, with 130 million light-sensitive cells ready to turn the light into electrical signals; these signals are carried away by the optic nerve. Once the information is transmitted, the brain combines the slightly different images from each eye, flips the image right-side-up, and adds detail.
Common eyesight conditions and diseases include refractive errors, age-related macular degeneration (AMD), cataracts, glaucoma and strabismus. The term “refractive errors” encompasses near-sightedness, farsightedness, astigmatism (distorted vision at all distances) and reduced ability to focus up close. Proper refractive correction could improve the vision of several million Americans, according to the NEI. AMD affects the macula and comes in two forms. “Wet” AMD presents as rapid vision loss caused by damage from blood vessels growing abnormally under the macula. Most cases of AMD are “Dry” and are characterized by gradually blurring vision. The thinning of the macula—a normal part of aging—is the culprit. A common early sign of AMD is the presence of drusen. Cataracts are the leading cause of blindness worldwide and are a result of clouding in the eye lens. Glaucoma is a group of diseases that may result in vision loss due to optic nerve damage. Strabismus, an imbalance in eye positioning, can cause the eyes to cross or turn out. It can also cause amblyopia, commonly known as a lazy eye.
In order to maintain eye health, the CDC recommends regular comprehensive dilated eye exams; drops are used to widen the pupils, allowing eye care professionals to check for common vision problems. Other ways to protect one’s sight include wearing protective eyewear at work or during sports, knowing your family’s eye health history, and using sunglasses that block 99-100% of UVA and UVB radiation. Particularly during the pandemic and rising screen usage, giving eyes a break is critical. Using the 20-20-20 rule–every 20 minutes, spend 20 seconds looking at something about 20 feet away–can help reduce eye fatigue. Healthy vision can help with holistic health. There is a correlation between vision issues and heart problems, diabetes, reduced hearing capability, and increased risk for depression. For those interested in promoting healthy vision in their communities, the CDC and NEI both offer several resources.
Image courtesy of https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/how-eyes-work
Resources