Refractive Errors

What is Farsightedness (Hyperopia)?

Farsightedness or hyperopia affects about ¼ of the North American population. Farsighted people may see things in the distance, but cannot see clearly up close.

This vision problem occurs when light rays entering the eye focus behind the retina, rather than directly on it. The eyeball of a farsighted person is shorter than normal. Farsighted people sometimes have headaches or eye strain and may squint or feel fatigued when performing work at close range.  This condition can be confused with presbyopia.

You may need to wear your glasses or contacts all the time or only when reading, working on a computer or doing other close-up work. Farsightedness can also be corrected with laser refractive surgery.

What is Astigmatism?

Astigmatism usually is caused by an irregularly shaped cornea. Instead of the cornea having a symmetrically round shape like a soccer ball, it is shaped more like a football where the curvature is greater in twodirections.

In an eye with astigmatism, light fails to come to a single focus point on the retina to produce clear vision, instead multiple focus points occur. Either in front or behind the retina (or both). Astigmatism usually causes vision to be blurred or distorted to some degree at all distances.

Symptoms of uncorrected astigmatism are eye strain and headaches, especially after reading or other prolonged visual tasks. Squinting also is a very common symptom of uncorrected astigmatism.

Astigmatism often occurs early in life, so it is important to schedule an eye exam for your child to avoid vision problems in school from uncorrected astigmatism. Astigmatism usually can be corrected with eyeglasses, toric contact lenses or refractive surgery.

Focusing problems like astigmatism can be corrected with corrective lenses or refractive surgery.

What is Presbyopia? What is the need for reading glasses?

Presbyopia, a focusing problem that develops in most people around the age of 40, occurs when people experience blurred near vision or a lag in focusing.

When people develop presbyopia, they find they need to hold books, magazines, newspapers, menus and other reading materials at arm’s length in order to focus properly. They may also experience headaches, eye strain or feel fatigued.

Presbyopia is caused by an age-related thickening and a loss of flexibility of the lens inside the eye along with a loss of elasticity of the muscle fibers surrounding the lens.

Eyeglasses with bifocal or progressive addition lenses (PALs) are the most common correction for presbyopia. Other corrections include reading glasses, multifocal contact lenses, monovision contact lenses, and laser refractive procedures.

What is Myopia?

Myopia, commonly known as nearsightedness, is the most common refractive error and has become more prevalent in recent years. The exact cause for this increase is unknown but has been linked to eye fatigue from prolonged computer use, other extended near vision tasks, and/or a genetic predisposition for myopia.

Nearsighted individuals have difficulty seeing distant objects clearly ex. Road signs, but are able to see well for close-up tasks such as reading. Signs and symptoms of myopia include squinting, eye strain and headaches.

Myopia occurs when the eyeball is too long causing light rays to focus at a point in front of the retina, rather than directly on its surface. Nearsightedness can be corrected with glasses, contact lenses or refractive surgery. Depending on the degree of your myopia, you may need to wear your glasses or contact lenses all the time or only when you need clear distance vision ex. driving, seeing a chalkboard or watching a movie.