In the U.S., 75% of adults need some form of vision correction. If you’re one of these adults who needs eyeglasses or contact lenses to fix their vision, the reason all comes down to how light enters your eye. How the light focuses on your retina means you are either nearsighted or farsighted.
Nearsightedness and farsightedness are not eye diseases. They are known as refractive errors, or slight abnormalities that affect the eye’s ability to focus light. When light enters your eye through the pupil, it needs to be focused on a thin layer of tissue in the back of your eye in order for you to see clearly. This layer is the retina.
When light enters your eye and does not focus properly on your retina, it causes blurry vision. For nearsightedness and farsightedness, the difference is where the light focuses inside your eye.
But that’s just the beginning. Here we break down the differences between nearsightedness and farsightedness.
First of all, normal vision occurs when light is focused directly on your retina rather than in front or behind it. Someone with normal vision can see objects near and far away.
If you are nearsighted, light focuses in front of your retina instead of directly on it. This causes distant objects to look blurry but objects nearby appear in focus.
Medical term: myopia
Cause: The shape of your eyeball is too long from front to back
Development: Typically develops during periods of rapid growth when you are a child or teenager; usually stabilizes during adulthood
How common: According to the National Health Institute, about 40% of Americans are nearsighted, four times more than those who are farsighted
If you are farsighted, light focuses behind your retina instead of directly on it. This causes close objects to look blurry and objects in the distance to appear in focus.
Medical term: hyperopia
Cause: The shape of your eyeball is too short from front to back
Development: Usually present from birth; you can also become farsighted with age
How common: According to the National Health Institute, only 5% to 10% of Americans are farsighted
What about our vision as we age?
Most people experience vision changes as they age. In fact, an estimated 85% of adults over age 45 have age-related farsightedness. This is a natural part of the aging process called presbyopia. As we age, our eyes lose the ability to focus and the lenses harden and lose their natural flexibility. While this can’t be prevented, it can be corrected with reading glasses, bifocal lenses or progressive lenses.
What about astigmatism?
Astigmatism is another kind of refractive error. It’s caused by subtle flaws in the way your eye bends light that passes to your retina. It can cause blurry vision at all distances.
Your vision If you experience any trouble seeing objects that are far away or close, but sure to schedule an exam with an optometrist. Members of BCBS FEP Vision enjoy fully-covered comprehensive vision care exams. To find an eye care provider near you, use our Find a Provider tool.