Nearsightedness is an eye condition in which you can see nearby objects clearly, but faraway objects appear fuzzy or blurry. Nearsightedness is also called myopia.
How does the eye work?
Nearsightedness is caused by a refractive error. A refractive error occurs when your eye does not focus light correctly. If you are nearsighted, your eye focuses light entering the eye in front of the retina instead of onto the retina.
The retina is the surface at the back of your eye that collects light. The retina changes the light into electrical impulses that your brain reads as images.
A myopic, or nearsighted, eye focuses incorrectly because its shape is slightly abnormal. A nearsighted eyeball is usually a little too long, and sometimes, its cornea is too rounded. The cornea is the clear covering on the front of your eye.
Risk factors for nearsightedness
According to the National Eye Institute (NEI), myopia is usually diagnosed between the ages of 8 and 12. (NEI) Your eyes are growing at this age, so the shape of your eyes can change. Adults usually remain nearsighted if they have the condition as a child. Adults can also become nearsighted due to certain health conditions, such as diabetes.
Visual stress can also be a risk factor for nearsightedness. Visual stress is eyestrain from doing detailed work, such as reading or using a computer.
Nearsightedness can also be an inherited condition. If one or both of your parents are shortsighted.
Symptoms of nearsightedness
The most obvious symptom of nearsightedness is blurry vision when looking at faraway objects. Children may have trouble seeing the blackboard at school. Adults might not be able to see street signs clearly while driving. Other signs of nearsightedness include:
• eyes that hurt or feel tired
The symptoms of nearsightedness usually go away after treatment with eyeglasses or contact lenses. Headaches and eye fatigue may linger for a week or two as you adjust to your new eyeglass or contact lens prescription.
Your eye doctor can diagnose nearsightedness by performing a complete eye exam. Correction for nearsightedness may include:
• corrective lenses
• corneal refractive therapy
• refractive surgery
Eyeglasses and contact lenses are examples of corrective lenses. These devices compensate for the curvature of your cornea or the elongation of your eye by shifting the focus of light as it enters your eye.
Your prescription strength will depend on how far you can see clearly. You may need to wear corrective lenses all the time or just for certain activities, such as driving.
Contact lenses generally give you a wider field of corrected vision than glasses. Contact lenses are applied directly to the corneas of your eyes. Some patients cannot tolerate contact lenses because they irritate the surface of their eyes.
Refractive surgery is a permanent form of correction for nearsightedness. Also called laser eye surgery, the procedure reshapes your cornea to focus light onto the retina. Most people who have refractive eye surgery no longer need to wear contact lenses or eyeglasses.