Nearsighted or Farsighted, or Why Your Eyes Need Glasses

During an eye doctor appointment, you may be baffled by the complexity of the terms the doctor uses or may not completely understand what the doctor is trying to tell us. It can be difficult to remember the differences between refraction and refractive error, or nearsightedness and farsightedness. What does it all mean?

Basically, the quality of our vision is determined by how well each eye refracts, or focuses, light. A normal eye has the ability to refract light without the help of eyeglasses or contact lenses. However, if an eye cannot refract light without the help of a lens, the eye is said to have a refractive error.

There are two different refractive errors that can be present. If a person is only able to see objects that are close up, the person is said to be nearsighted. If a person can only see objects that are far away, the person is farsighted.

Nearsightedness

Nearsightedness, or myopia, is very common. In the eye, the retina is the part of the eye that is sensitive to light. In order for vision to be sharp, the image must focus directly on the retina. Nearsightedness is caused when the light rays that make up an image are focused in front of the retina.

Though myopia can be caused by a number of reasons, it is most frequently the result of having a change in the shape of the eyeball from round to egg-shaped. This change of shape changes the way that light refracts in the eye, causing the light to focus in front of the retina instead of directly on the retina. Some of the symptoms of nearsightedness include:

• blurred vision or squinting when trying to see objects that are far away,
• eyestrain, and
• headaches.

Nearsightedness is hereditary. There are some risks involved with being severely myopic, which include having an increased risk of glaucoma and retinal detachment.

Farsightedness

Farsightedness, or hyperopia, is also very common. It occurs when the eye is too short lengthwise, and cannot bend light properly. This causes the image to focus light behind the retina, instead of directly on it, causing the image to become blurry. With farsightedness, people are able to easily see objects that are far away, but have a difficult time seeing objects that are directly in front of them.

Very often, farsightedness develops in early childhood, but as the child ages the problem is automatically corrected. As we age, our eyes can no longer correct the problem as well, and we may notice the farsightedness more obviously. The symptoms of farsightedness include:

• blurred vision,
• eyestrain,
• headaches, and
• trouble seeing objects up close.

Farsightedness is also hereditary.

Treatment

When dealing with nearsightedness or farsightedness, there are several things that can be done. For both, contact lenses or glasses may be worn to correct the errors. Or for a more permanent solution, laser eye surgery can be performed.

Laser surgery can be performed on both nearsighted and farsighted patients. The goal of laser surgery is to reshape the eye to change the way that light is focused. During laser surgery, a laser or an instrument called a microkeratome is used to create a thin, circular flap in the cornea. The surgeon folds that flap back, and removes some of the tissue of the cornea underneath using an excimer laser. This laser uses an ultraviolet light beam to remove tiny pieces of tissue from the cornea to reshape it. When the cornea is reshaped, it is able to focus light better on the retina and can result in much sharper vision than before. The flap is then put carefully back in place.

Although being nearsighted and farsighted are complete opposites, their symptoms are similar, and both can be corrected in a similar fashion. By modifying the way our eye focuses light through the use of glasses, contacts, or laser surgery, we are able to see objects more clearly and enjoy all of the benefits that life has to offer.

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