Myopia is the condition when one is suffering from near-sighted eyes
. Near-sighted eyes are those which face difficulty in seeing objects which are placed far. The word myopia is a Greek word from which the English translation came up as near-sightedness. The near-sighted eye is also said to be shortsighted or the condition is called short sightedness. This is a refractive defect in the eye where the collimated light creates an image focus that forms in front of the retina of the eye, when there is a relaxation in the accommodation. Comparatively there are only a few people who have perfectly healthy eyes. People who are suffering from the near-sightedness have difficulty in seeing far away objects clearly, they have a blurred vision, but can see nearby objects very clearly.When one is suffering from myopia, there is a change in the size of the eyeball as the eyeball become larger or there is some extra steepness in the cornea of the eye. Because of this the vitreous fluid in the eye has the images focused instead of the eyes retina, which is present at the back of the eye.
The optometrists and ophthalmologists correct the problem of near-sighted eyes by the use of corrective lenses, for the needs for vision for seeing clearly. The corrective lenses can include glasses or even the contact lenses. There is also a refractive surgery available for correcting the myopic eyes and one of the popular treatments is LASIK. The corrective lenses are concave which have their power optically negative. But since the myopic eyes have excess positive diopters that only balance with the negative diopters and one can see the far placed objects clearly. For patients who are suffering from low level shortsightedness, for them many a times pinhole glasses are recommended. These function by decreasing the blur circle that has been formed on the retina. According to cause, myopia is classified into Axial myopia where the eye`s axial length has increased and Refractive myopia which deals with the eyes refractive elements. The latter is further classified into Curvature myopia and Index myopia.Near-sighted eyes can also be categorized according to the clinical appearance. The most common type of myopia is simple myopia. In this case, the eye is optically too powerful compared to the axial length of the eyes. Degenerative myopia which is malignant is characterized by a subnormal acuity of the vision after correction. Nocturnal myopia or night myopia, also called as twilight myopia is where the eyes find it difficult to see in the areas with low illumination even though the daytime vision is normal. Pseudomyopia is where the vision blurs when the distance increases. Induced myopia better known as acquired myopia occurs when eyes are exposed to pharmaceuticals, rise in glucose level, nuclear sclerosis and others. Even cataracts can contribute to this defect.