Myopia refers to blurry eyesight caused by nearsightedness, or the inability of the eye to focus on objects at a particular distance away.
Myopia (nearsightedness) is a refractive error. Refractive error is when the eye does not bend (refract) light properly. Light does not focus correctly so images are not clear. In myopia, close objects look clear but distant objects appear blurred. Myopia is a common condition that affects an estimated 25% of Americans.
Myopia may be inherited. If a parent has myopia their child may get is as well. Myopia is often discovered in children when they are between ages 8 and 12 years old. During the teenage years, when the body grows rapidly, myopia may become worse. Between the ages of 20 and 40, there is usually little change. Myopia can also occur in adults.
High myopia or Pathological myopia is an extremely high amount of nearsightedness usually above -6.00 diopters (worse than 20/400 uncorrected vision). This causes a major alteration of the shape or globe of the eye, which may lead to profound vision loss. In the United States, it occurs in about 2% of the population and is the seventh leading cause of legal blindness.
A number of possible complications can occur due to High myopia or Pathological myopia:
• The retina's center (macula) thinning with age. While this does not affect side (peripheral) vision, the ability to focus on a particular object (like reading a sign) diminishes and is eventually lost.
• Retinal thinning can also lead to tears and holes, which can cause the retina to detach. (Learn more about retinal detachment.)
• The retina can split, a condition called myopic retinoschisis (MRS).
• Layers of the eye under the retina can degenerate or crack, allowing new, faulty blood vessels to grow under the retina, a process called choroidal neovascularization (CNV). The vessels can bleed and scar, with small scars causing minor macular damage and larger ones more significant problems.
• Increased eye pressure may lead to glaucoma.
• Cataracts are more likely to develop.
• The eyes become more susceptible to injuries and other traumas, like surgery.