Common Eye Disorders > Refractive Errors

The cornea and lens bend or refract light rays so they can be focused on the retina, the nerve layer that lines the back of the eye. The retina receives the picture formed by these light rays and sends the image to the brain through the optic nerve. A refractive error means that the shape of the eye does not allow the light to be properly refracted making images blurry.

Refractive errors include:

  • myopia (nearsightedness)
  • hyperopia (farsightedness)
  • astigmatism
  • presbyopia
  • monovision

What is myopia (nearsightedness)?

Myopia (nearsightedness) occurs when light rays are focused in front of the retina instead of directly on the retina. Nearsighted people have difficulty seeing objects at a distance, such as highway signs, but usually can see up-close for tasks such as reading or sewing.

What is the treatment for myopia?

Non- surgical treatment options for myopia include glasses and contact lenses. Surgical treatment options include, clear lens extraction, LASEK, LASIK, PRK and phakic IOLs. While there are numerous surgical options available, not all individuals are good candidates for specific procedures. Patients should review these options in depth with their ophthalmologist prior to making any final decisions.

What is hyperopia (farsightedness)?

Hyperopia or farsightedness occurs when light rays are not bent enough to focus on the retina. People with hyperopia can sometimes see distant objects very well, but may have difficulty seeing objects that are close.

Young eyes can sometimes compensate for this refractive error, depending on age and the degree of hyperopia present. But with aging, the human lens loses this ability and a hyperopic person eventually may have difficulty seeing objects at a distance, as well as those that are nearby. In fact by age 40, even those with little or no refractive error will begin to experience difficulty focusing on close objects. This is known as presbyopia

What is the treatment for hyperopia?

Non-surgical treatment options include glasses and contact lenses. Surgical treatment options include clear lens extraction, LASIK eye surgery, LASEK, PRK and phakic IOL.While there are numerous surgical options available, not all individuals are good candidates for specific procedures. Patients should review these options in depth with their ophthalmologist prior to making any final decisions.

What is astigmatism?

Regular astigmatism occurs when light rays are focused at more than one point on the retina. Astigmatism is the most common vision problem. It occurs when the cornea surface is not ideally rounded, but is curved more along one axis than the other — that is, when the eye is shaped more like the side of a football than a soccer ball. Light entering the eye does not focus symmetrically on the retina. The result is astigmatism, which blurs both near and distance vision. This refractive error may occur in patients who are either myopic (nearsighted) or hyperopic (farsighted). There are various types of astigmatism included regular, mixed and irregular astigmatism.

What is the treatment for astigmatism?

Patients with only a small amount of astigmatism may not notice it or may have slightly blurred vision. Non-surgical treatment options include glasses and contact lenses. Surgical treatment options include LASIK eye surgery,LASEK and PRK.

What is presbyopia (age-related difficulty with near vision)?

With increasing age, the lens inside of the eyes loses the ability to focus on nearby objects. The problem usually manifests itself around age 40 and can be corrected with bifocals or reading glasses. This is a normal aging process.

What is the treatment for presbyopia?

Non-surgical treatment options include glasses usually multifocals or bifocals and contact lenses. Surgical treatment options include LASIK eye surgery, LASEK and PRK usually using a technique known as monovision. More advanced options include putting a multifocal intraocular lens in the eye usually at the time of cataract surgery.

What is monovision?

Monovision is a method of correcting presyopia, and essentially leaves one eye for near and one eye for distance. This is achieved either through contact lenses or refractive surgery. Contact lenses or glasses may be required for best distance or night vision activities, including driving. This option is not suitable for everyone and a trial period of monovision using contact lenses may help decide if it is right for you.

If you are researching refractive surgery, Lasik eye surgery in Cape Town or searching for an Ophthalmologist in Cape Town, please contact one of our practices where our qualified assistants are able to provide professional and friendly guidance.

Read more about Laser Surgery and Other Refractive Surgery Options.