Myopia, Hyperopia and Astigmatism
Nearsightedness, or myopia, is the most widespread refractive error of the eye. If you are nearsighted, you naturally will have difficulty reading road signs and seeing distant objects clearly, but you will be able to see well for close-up tasks such as reading and computer use.
Interestingly, nearsightedness or myopia has become more prevalent in recent years. A recent study by the National Eye Institute (NEI) shows the prevalence of myopia grew from 25 percent of the U.S. population (ages 12 to 54) in 1971-1972 to a whopping 41.6 percent in 1999-2004.
Other signs and symptoms of myopia include squinting, eye strain and headaches. Feeling fatigued when driving or playing sports also can be a symptom of uncorrected nearsightedness.
Narrated – Myopia
Hyperopia, or farsightedness, is a common type of refractive error where distant objects may be seen clearly while having issues seeing objects that are near. People experience hyperopia in different way, some people with significant hyperopia, vision can be blurry for objects at any distance, near or far.
Hyperopia develops in eyes that focus images behind the retina instead of on the retina, which can result in blurred vision. This occurs when the eyeball is too short, which inhibit in coming light from focusing directly on the retina. It may also be caused by a irregular shape of the cornea or lens.
Hyperopia can affect both children and adults. It affects about 5 to 10 percent of Americans. People whose parents have hyperopia may also be more likely to get the condition.
Narrated – Hyperopia
Astigmatism is an imperfection in the curvature of your eye’s cornea or lens. In a normal lens, the cornea and lens are smooth and curved evenly in all directions. This assists us in focusing light rays sharply onto the retina at the back of your eye.
If your cornea or lens isn’t smooth and evenly curved, light rays are not refracted (bent) properly. Doctors call this a refractive error. When your cornea has an irregular shape, you have corneal astigmatism. When the shape of your lens is distorted, you have lenticular astigmatism. In either case, your vision for both near and far causes objects to be blurry or distorted. Best example is looking into a fun house mirror in which you can appear too tall, too short, too wide or too thin.
You can have astigmatism along with Myopia and or hyperopia.