The eye is one of the most complex systems of the body. Even for those who know a lot about the eye, it’s still a wonder how we’re able to see! So for the everyday person, it’s understandable if you have trouble deciphering your prescription. To help you get to know your eyes and eyesight a little better, here’s a basic guide to the two most common eye conditions, nearsightedness and farsightedness.

What is nearsightedness?

Nearsightedness, or myopia, is when you can see things close to you, but things get blurry at a distance. 40% of Americans are nearsighted, making this a very common issue. If your prescription contains a negative number (-), this indicates you have myopia. A larger prescription number means more correction is needed.

What is farsightedness?

Farsightedness, or hyperopia, is the opposite of nearsightedness. If you have hyperopia, you are able to see things that are far away, but things up close are blurry. This is a rarer condition, affecting only 5-10% of Americans. If your prescription contains a positive number (+), this indicates you have hyperopia. A larger prescription number means more correction is needed here as well.

However, needing reading glasses may not mean you are farsighted. You may have presbyopia, which is common in old age. It is when the lens of the eye becomes thicker and hardened and seeing things up close becomes blurry.

What causes nearsightedness and farsightedness?

Now that we know the difference, what causes these conditions? First, it helps to understand how we see. In simple terms, light enters your eye, filters through the cornea and lens which helps to focus it directly onto your retina. Your retina sends the light through the optic nerve and to your brain to process it into the image you see. Nearsightedness and farsightedness happen when light isn’t able to precisely reach your retina due to the shape of the eye and/or cornea. That’s why these two conditions are referred to as refractive errors.

In the case of nearsightedness, the light is focused in front of the retina, not quite reaching it because of an eyeball that is shaped too long or a cornea that is too curved for light to hit the retina correctly.

Farsightedness is when the light is focused behind the retina, aiming past it because the shape of the eyeball is too short or the cornea is too flat for light to hit the retina correctly.

No matter what condition you have, corrective lenses can help you see better.

If you haven’t seen your eye doctor already, it’s important to get an expert diagnosis so that you can get the right corrective lenses to help you see clearly. Then, you’ll be free to explore the many styles of glasses and brands of contact lenses that best suit you!