19 Aug Nearsightedness and farsightedness, all you need to know
Normal vision occurs when light is focused directly on the retina rather than in front of or behind it. A person with normal vision can see objects clearly near and far away. Nearsightedness and farsightedness are two very common vision conditions. Both of them are refractive errors or abnormalities of the eye that affect the ability to focus light on the retina.
The medical term for nearsightedness is myopia. A nearsighted person sees near objects clearly, while objects in the distance are blurred. Myopia is the most common cause of impaired vision in people under the age of 40. In recent years, its prevalence is growing at an alarming rate.
This occurs when light entering the eye does not focus properly on the retina, the membrane that lines the back of the eyeball. Instead, the light falls short — usually because the eyeball has grown too long. Nearsightedness often develops in the rapidly growing school-aged child or teenager, and progresses during the growth years, requiring frequent changes in glasses or contact lenses.
Farsightedness, or hyperopia, is somewhat the opposite of nearsightedness. A farsighted person sees faraway objects clearly, while objects that are near are blurred. It usually is caused by an eyeball that is too short, which causes light to come to a focus behind the retina instead of directly on it.
Farsightedness is often present from birth, but children can often tolerate moderate amounts without difficulty and most outgrow the condition. Typically, farsightedness makes close objects appear to be out of focus, while distant objects remain clear. But high amounts of hyperopia may cause objects at all distances to be blurry. Mild cases of farsightedness might not affect vision at all but cause headaches when reading or doing other close work.
Nearsightedness and farsightedness share some common symptoms, including headaches, eye strain, squinting to see clearly, and eye fatigue. Experiencing any of these symptoms is an indication that a comprehensive eye exam with an optometrist or ophthalmologist is needed to determine a diagnosis and treatment options.
Treatment for nearsightedness and farsightedness
Both nearsightedness and farsightedness can be treated with corrective eyeglasses and contact lenses. The lenses work by changing the way light rays bend into the eyes. Many people find that their nearsightedness or farsightedness stabilises once they’re in their twenties. When there is no more change in refractive error, LASIK and PRK are two surgical procedures that can permanently correct myopia or hyperopia by reshaping the cornea so light comes to a clear focus on the retina.
To determine if you have nearsightedness or farsightedness, schedule an eye exam with an eye doctor near you. Visit our contact us page to get in touch with Sandton Eye Clinic.