What Is Myopia? - Definition, Causes & Symptoms

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

Myopia is the medical term for nearsightedness. I, the writer of this fascinating lesson, am part of the 30% of Americans who are nearsighted. Read more to learn what causes this condition and what the specific symptoms are.

What Is Myopia?

Myopia is the medical term for nearsightedness. This is a refractive disorder of the eye where a person sees objects clearly when they are up close, but they become blurry once they are far away. Approximately 30% of the population in the USA suffers from myopia.

Myopia generally first occurs in younger children between the ages of 6 and 12, and the eye continues to adjust until at least age 20. Kids who suffer from myopia may need new corrective lenses made every year until their eyes stop adjusting. However, myopia can also occur in adults with no prior vision problems.

What Causes Myopia?

Myopia occurs when the eyeball is too long or the cornea is abnormally shaped and has too much curvature. The cornea is the clear outer covering of the eyeball. Because of these morphological differences, light does not focus correctly when it enters the eye, thus making objects that are distant look blurry. Instead of light focusing on the retina itself, light focuses in front of the retina, and this causes the myopic symptoms. There is a debate whether myopia is hereditary or caused by excessive eye strain, though it is likely due to a combination of the two. Individuals who spend a great deal of time on the computer or reading are more likely to develop myopia.

Myopia is a condition where light focuses in front of the retina rather than on the retina.

Myopia Symptoms and Treatment

The primary symptom of myopia is blurred vision when viewing distant objects. Usually, if someone is experiencing myopia, they will squint or frown when trying to focus on objects that are far away. They may also experience eyestrain and headaches. In some cases, symptoms may only occur at night or when blood sugar is low.

An optometrist can diagnose myopia by performing a vision exam. If vision is dramatically obscured, glasses or contact lenses can be worn to counteract the problem, and this is the most common treatment type. Specialized contact lenses that actually reshape the curvature of the eye may lessen the symptoms of myopia, or surgical procedures may reshape the cornea. If myopia is stress-related, vision therapy may help correct the problem.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account