Is it hard to see distant objects, like highway signs, until you’re a few feet away, but easy to read a book up close? Chances are you’re myopic, also known as nearsighted. It’s a pretty common condition that your eye doctor usually can fix with eyeglasses, contacts, or eye surgery.
What Causes Myopia?
The structure of your eye is to
blame. When your eyeball is too long or the cornea -- the protective outer layer of your eye -- is too curved, the light that enters your eye won’t focus correctly. Images focus in front of the retina, the light-sensitive part of your eye, instead of directly on the retina. This causes blurred vision. Doctors call this a refractive error.
High myopia: It’s a more serious form of the condition, where the eyeball grows more than it is supposed to and becomes very long front to back. Besides making it hard to see things at a distance, it can also raise your chance of having other conditions like a detached retina, cataracts, and glaucoma.
Degenerative myopia: Also called pathological or malignant myopia, it is a rare type you usually inherit from your parents. Your eyeball gets longer very quickly and causes severe myopia, usually by the teenage or early adult years. This type of myopia can get worse far into adulthood. Besides making it hard to see things at a distance, you may have a higher chance of having a detached retina, abnormal blood vessel growth in the eye (choroid neovascularization), and glaucoma.
Chances are the only symptom is that more distant objects are blurred. You may also notice:
- Eye strain
- Eye fatigue when you try to see objects more than a few feet away
- Children with myopia often have trouble reading the blackboard at school.
Diagnosis and Treatment
An eye exam can show you if you’re myopic. Glasses, contacts, or refractive surgery can usually correct the problem.
When you have myopia, your prescription for glasses or contact lenses will be a negative number. The more negative the number, the stronger your lenses will be. For example, -3.00 is stronger than -2.50.