Scientists Say: Myopia

This is the scientific term for nearsightedness, in which people have trouble seeing distant objects


People sometimes have to wear glasses because they have myopia — a condition where distant objects appear fuzzy.

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Myopia (noun, “My-OH-pee-ah”)

This term describes a condition called nearsightedness — when someone has trouble seeing objects that are far away. Usually, someone with myopia can read a book or smartphone without trouble. But they might view objects even an arm’s length away as fuzzy and out of focus.

When light enters the eye, it passes through the outer layers — the cornea — and then through a lens. The lens focuses the light to a point on the back of the eyeball in an area called the retina.  There, nerve cells process the information and pass it on to the brain.

When the eyeball is a perfect sphere, the light becomes focused on just a small point on the retina. That produces perfect vision. But if the eyeball is slightly too long from front to back, the light will focus to a point before it hits the retina. Then, the light spreads out again. The more the light spreads out before it hits the retina, the fuzzier the image will appear to the viewer. A too-thick cornea will also make the light focus too early. Both of these changes can produce myopia.

Glasses and contact lenses can help people with myopia. These objects help focus light when the eyes aren’t quite up to the job.

The eye on the left is a perfect sphere. When light enters, it focuses, or narrows, to a point on the retina at the back of the eye. This produces normal vision. The eye on the right is slightly elongated. When light enters, it focuses in front of the retina, then it spreads out again. This produces a fuzzy-looking image to the viewer. The person on the right would have myopia.
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In a sentence

Spending time outdoors as a kid might help reduce the risk for myopia.

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

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