Vision+defects

Astigmatism generally indicates that the cornea is not spherical. That is, the cornea in astigmatism is sometimes referred to as hav
=== ing a football shape rather than a basketball shape. More specifically, the cornea is steeper in one meridian, and flatter in the opposite meridian 180 degrees away. ===

=== In some cases, astigmatism occurs primarily as a consequence of the lens of the eye (lenticular astigmatism). In either case, or even if there is a combination of corneal and lenticular (lens induced) astigmatism, the result is two separate points of focus in the back of the eye. To the affected individual, vision is simply blurred or in some cases even distorted. Astigmatism of some degree is present in approximately 30 to 40% of individuals who wear glasses or contact lenses. ===

=== Hyperopia, or farsightedness, occurs when images are formed behind the resulting in a blurred image. This is due to an eye that is relatively too short, or ===

=== the refractive powers of the cornea and lens of the eye are relatively too weak. Depending on the degree of farsightedness and the age of the individual, some farsighted people may see clearly at both distance and near through the process of accommodation, or focusing of the lens in the eye. This may cause significant eyestrain, however, and accommodative abilities are gradually lost with aging. ===

**Nearsightedness**
====== === Myopia, or nearsightedness, is the condition of the eye in which images are formed in front of the resulting in a blurred image. This occurs when the eye is relatively too long or the refractive powers of the cornea and lens of the eye are relatively too strong. Myopia usually begins in childhood, and progressively worsens until adulthood is achieved, usually about 18 to 21 years of age. ===