Refractive Errors

Understanding (Myopia, Hyperopia and Astigmatism).

If you can see objects nearby with no problem, but reading traffic signs or making out the writing on the board at the mall center is more difficult, you may be near- or shortsighted. Your eye doctor may refer to the condition as myopia, a term that comes from a Greek word meaning "closed eyes." Use of the word "myopia" for this condition may have grown out of one of the main indications of nearsightedness: Squinting to see distant objects clearly.

Myopia

Myopia is not a disease, and it does not mean that you have "bad eyes." It simply refers to a variation in the shape of your eyeball. The degree of variation determines whether or not you will need corrective eyewear.

Myopia, is a condition that makes it difficult to see objects that are far away. This is because the focal point sits right before the retina, located in the back of the eye. The most common reason for this is that the eye is too long. Myopia can be caused by both environment and genetics and it is more prevalent with some ethnic groups than others.

Myopia can be corrected with eye glasses, contact lenses, refractive surgery (Cataract surgery) and LASIK surgery.

myopia

Note: For additional information, is our pleasure to refer you to the following Myopia resource.

Hyperopia

If you can see objects at a distance clearly but have trouble focusing well on objects close up, you may be farsighted. Your eye doctor may refer to farsightedness as hypermetropia or hyperopia. Hyperopia causes the eyes to exert extra effort to see close up. After viewing nearby objects for an extended period, you may experience blurred vision, headaches and eyestrain. People who are farsighted may find reading difficult.

Once again, Hyperopia is not a disease. It simply means that you have a variation in the shape of your eyeball. The degree of variation will determine whether or not you will need corrective lenses.

This is because the focal point appears behind the retina, usually because an eye is too short or the eye has poor focusing power. A convex lens, or one which protrudes outwards, can adjust the focal point so that it sits at the retina. Children with hypermyopia will sometimes appear cross-eyed and adults will notice frequent headaches and pain from straining to see close up objects.

Hyperopia can be corrected with eye glasses, contact lenses, refractive surgery (Cataract Surgery) and LASIK surgery.

hyperopia

Astigmatism

If you experience a distortion or blurring of images at all distances nearby as well as far you may have astigmatism. Even if your vision is fairly sharp, headache, fatigue, squinting and eye discomfort or irritation may indicate a slight degree of astigmatism. A thorough eye examination, including tests of near vision, distant vision and vision clarity, can determine if astigmatism is present.

Astigmatism is not a disease. It simply means that you have a variation or disturbance in the shape of your cornea or in your natural intraocular lens (crystalline), which makes it hard for the eye to focus.

When astigmatism is present, the surface of the cornea is distorted instead of being spherical. It is unable to focus light rays entering the eye into the fine point needed for clear vision. At any time, only small proportions of the rays are focused and the remainder is not, so that the image formed is always blurred. Usually, astigmatism causes blurred vision at all distances. Around 30% of the population has some degree of astigmatism, and can be corrected with eye glasses, contact lenses and (LASIK surgery as long as the astigmatism is located in the surface of the cornea and not in the intraocular lens).

astigmatism

Page updated February 05, 2010