Myopia
More than 70 million people in North america (about one in four) are nearsighted. Myopia is the medical term for nearsightedness. It occurs when your eye is too long in relation to the curvature of your cornea. Myopia causes light rays entering the eye to focus in front of the retina, produccing a blurred image.

The term "nearsighted" means that you can see objects that are "near" to you more clearly than distant objects. The more myopic you are, the more blurred distant objects appear, the higher your prescription in diopters,and the thicker your glasses.

Hyperopia
Hyperopia is the medical term for "farsightedness." Hyperopia occurs when your eye is too short in relation to the curvature of your cornea. Light rays entering your eye focus behind the retina, producing a blurred image. Some farsighted people can use their focusing muscles to pull the image forward onto the retina, allowing them to see clearly. But others who cannot overcome the effects of severe hyperopia, need reading glasses or bifocals.

Astigmatism
Many patients with myopia and hyperopia have some degree of astigmatism, or ovalness, to their cornea. It occurs when your cornea is shaped more like a football than a basketball. As a result, you experience distortion or tilting of images due to the unequal bending of light rays entering your eyes. Prople with high degrees of astigmatism have blurred vision for both near and distant objects.Astigmatism is also measured in diopters.

Presbyopia
Presbyopia is part of the normal process of aging and is not corrected with the laser. It develops as the lens of the eye loses some of the flexibility that characterizes a younger eye. Everyone experiences the effects of presbyopia, typically between the ages of 40 and 50.Nearsighted people who become presbyopic may require bifocals in their forties, and those who never needed glasses before may require reading glasses.

Mild myopia counteracts presbyopia. That is why, if you're slightly myopic, you can remove your glasses and still be able to read, even after presbyopia sets in. After having laser vision correction, your myopia may be gone, and you will need reading glasses for fine print to correct your presbyopia like other normally sighted individuals.

Q: What Can I Do About My Presbyopia?
Q: Which Is Better for Treating Presbyopia: Soft Contacts or GPs?

Q.What Can I Do About My Presbyopia? A: Presbyopia can be easily corrected with reading glasses. However, most people already require some form of vision correction to see at a distance, which means that they now have two or even three pairs of glasses to worry about. Rather than switching between different pairs of glasses all day, you have a few options that can give you the best of both worlds. MULT/FOCAL CONTACT LENSES are the best option avail­able today. They use various zones of magnification to help you see both close up and far away without wearing glasses. These popular contacts are preferred over monovision because they create a natural range of vision similar to that of the normal eye. In addition, they correct both long- and short-range vision as well as astigmatism without any obvious drawbacks. B/FOCAL EYEGLASSES combine both distance and close-range lenses together. Each lens has a distance portion on top and a close-range portion on the bottom so you can switch back and forth without changing glasses. One drawback of bifocals is that people can usually see the line between one segment of the lens and the other. Another is that some people have trouble seeing the middle range between distance and near vision. Trifocals are just like bifocals except they have three sections to accommodate the middle range of vision as well. PROGRESSIVE LENS EYEGLASSES are a newer, more expensive version of bifocals and trifocals that blend the different lens segments together to create a natural range of vision similar to that of the normal eye. Progressive lenses also eliminate the obvious line seen in bifocals, which helps patients who are concerned about their appearance. MONOV/S/ON is a technique using contact lenses in which you wear a close-range contact in one eye and a distance-range contact in the other. Your brain will most likely adapt to the change and be able to see reasonably well throughout your range of vision within a few days to a month. This is an appealing technique for people who don't want to wear glasses; however, you will most likely experience a loss of depth perception. B/FOCAL CONTACT LENSES combine both distance and close-range lenses together. Each lens has a distance portion on top and a close-range portion on the bottom. The lenses are usually weighted so that the lens shifts and then maintains the position of the near and far zones. Q.Which Is Better for Treating Presbyopia: Soft Contacts or GPs? A: There are multifocal contact lenses made out of both soft-contact and gas permeable materials, but GP lenses offer better visual acuity. Eye doctors attribute this advantage to their firmness and limited movement. Since GPs keep their shape when you blink, and move around less, the near and far zones remain consistently in place. This reduces the need to refocus and the strain on your eye.