If you grew up with nearsightedness, you’ve heard it all. You didn’t eat enough carrots! You wore your glasses too much and made it worse! Those are both myths, for the record. So what DOES contribute to myopia, also known as nearsightedness?
Vision is the last sense that all humans develop as babies. In the womb, babies don’t open their eyes until around 26 weeks to protect their developing retinas. Once they are born, they can only see blurry objects about a foot in front of their face and have little to no color vision. At one-month-old, a baby can see more colors and track moving objects. By three months old, they can recognize familiar faces and have depth perception.
Three months old! That’s a lot of time to pass while vision is developing. Nutrition during this time period and during childhood does play a factor in vision development, but it’s not the largest factor.
The number one factor determining if you will develop myopia is typically considered to be genetics. Yep, thank your family for subpar vision and trips to the optometrist and optician every year. You are far more likely to develop myopia at some point in life if one or both of your parents grew up nearsighted.
It’s not all nature, there is some nurture involved in the road to needing eyeglasses. The way you use your eyes can contribute to nearsightedness. For example, children who may have inherited a tendency to develop myopia are more likely to ACTUALLY develop myopia if they do close-vision activities such as reading or using a computer often. Suddenly the stereotype of the nerdy kid with eyeglasses and a stack of books makes more sense.
An eye specialist can help determine the exact cause of your myopia, but basically, a mix of genetic and environmental factors result in an eyeball whose shape is too long or a cornea that is too curved. In both instances, light entering the eye cannot focus correctly, and you see farther objects as blurry and unfocused. The misshapen eyeballs and/or corneas tend to change as you develop up to age 20, which is why consistent visits to an eye specialist are important to keep your glasses prescription up to date.
Did you know you can develop false myopia from close-vision activities as well? Say you’re a 27-year-old who works long hours on your laptop. You’ve had 20/20 vision all your life. When you’re not working, you notice far-off objects looking more blurry than usual. Your eyes are essentially out of practice when it comes to focusing on farther objects.
Now, say you go on vacation for a week, and vow to leave the electronics at home while away. At the end of the week, your vision seems to have gone back to ‘normal’, that is, without far objects blurring. You are likely experiencing false or pseudo-myopia. The condition is usually temporary if you give your eyes enough rest. Careful, though — prolonged visual stress over time can leave permanent damage. If you or someone you know if experiencing anything like false myopia, it’s a good idea to get an opinion from an eye specialist.