Different Reasons Why People Have Eyeglasses

More than half the people in the U.S. wear glasses or contact lenses to improve eyesight. Eyeglasses have evolved from two magnifying glasses connected together and worn at the end of the nose into the prescription glasses worn today. There are a number of visual disorders which might require people to wear eyeglasses.

Nearsightedness

• Nearsightedness or myopia is a condition when people can see close objects clearly, but distant objects appear out of focus and blurred. This is due to a refractive error of the eye in which the image of the distant object is formed in front of the retina and cannot be seen distinctly. Nearsightedness is thought to be hereditary and affects more than 25 percent of the U.S. population. It normally becomes evident in childhood and worsens until early adulthood, although it is rare in infants.

Farsightedness

• Farsightedness or hyperopia happens when the eyeball is too short, meaning that the point of focus lies beyond the back wall of the eye. This means that when the light rays hit the retina they are still not yet in focus. Hyperopic people can see distant objects clearly with near objects being out of focus. In severe cases all objects can be blurred. Hyperopia is common in infancy with most children losing it by the time they are teenagers.

Astigmatism

• Astigmatism is when a curvature on the cornea and/or lens of the eye prevents light rays from being focused on a single point of the retina. This results in the person seeing a blurred image. This results in poor visual acuity on both near and far objects. The condition is often inherited.

Strabismus

• Strabismus or cross eye refers to eyes that are not straight or properly aligned. As the eye muscles are not working together, one eye might turn in as the other turns in a different direction. This condition can be constant or come and go. In some instances it can alternate between the eyes, with first one eye turning and then the other. This condition can occasionally be corrected with special eyeglass lenses and drops, and needs to be diagnosed early by visual screening.