What a picture might look like for someone with myopia
The picture that someone with normal vision sees
Diagram of the light focusing too far forward in the eye (top), and then the light focusing properly after it goes through a lens (bottom)Video explaining how myopia happens. (NIH)
Myopia, also called near-sightedness or short-sightedness, is a problem with the eye's ability to focus. It is when the eye is not able to focus properly on things that are far away.
It is very common. It normally happens when the eye is too long, so light entering the eye focuses on in front of the retina, rather than directly on it. This makes things that are far away look blurry. People with myopia often squint while watching television or trying to see things that are far away.
The best way to prevent myopia is to spend 2 hours outside every day. This is because sunlight stops eyes from growing. 2 hours outside every day prevents 50% of new myopia onset. This means that if 2 people would normally get myopia, if they both spend 2 hours outside every day, only 1 of them will get myopia.
Because the eye stops growing at some time between 15–20 years old (it is different for each person), myopia can't be prevented after someone is an adult.
Some people prefer glasses, while other people prefer contact lenses. Neither one is objectively better than the other; they both work well for most people, although a small minority of people can't use either of them. Glasses are always completely safe, but contact lenses can be dangerous if they're not used correctly. Contact lenses should always be kept in a proper container, and they should be taken out before showering and swimming. Some people prefer contact lenses because they don't fall off often, they can't become foggy, and they have better peripheral vision.
