Myopia Definition
Myopia, more commonly called near or short-sightedness, is characterized by a refractive defect of the eye wherein collimated light produces image focus in front of the retina when accommodation is relaxed.
Myopia Diagnosis
An eye examination done by an optometrist or ophthalmologist usually confirms a diagnosis of myopia. A retinoscope or an autorefractor is used to generate an initial evaluation of the refractive capabilities of the eye. Later, a phoropter is used to refine the patient's lens prescription.
Myopia Treatment
Myopia is commonly corrected with the use of corrective lenses such as prescription glasses and/or contact lenses. The corrective lenses may be concave or have a negative optical power, thus compensating for the excessive positive diopters of the eye. Less frequently, pinhole glasses, which reduce the blur cycle on the retina, are used by those with low level myopia. Recently, Refractive surgery, such as LASIK, has become a very popular means of correcting this condition.
Myopia Symptoms and Signs
For patients with myopia, nearby objects appear very clearly, while distant objects seem blurry. Individuals with this condition have either abnormally long eyeballs or excessively steep corneas. As a result, the images are focused in the vitreous inside the eye rather than on the retina of the back of the eye.
Myopia Causes
Several theories exist as to the origins of myopia. A combination of genetic and environmental factors is believed to play a role. For example, the work environment (such as daily exposure to computers, excessive reading habits, etc.) may aggravate an individual's retina, thus resulting in myopia. However, a genetic susceptibility to environmental conditions also leads to myopic progression.
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