LASIK and Eye Surgery Blog - Clearview Eye and Laser Medical Center

Many people know that myopia is nearsightedness, but what is nearsightedness exactly? Yes, it's the ability to see well up close but not at distances. What causes that?

The shape of the cornea (clear front part of the eye) causes it. We are all born with eyes of a certain shape. If the shape is within certain parameters, we have what is called 20/20 vision. Then we don't need glasses to see well at all distances.

A myopic eye has a steeper cornea than normal. Like all clear, curved structures, the cornea bends (refracts) light rays as they pass through it into the eye. The eye's lens, another clear, curved structure, does the same thing. To see clearly at all distances, the cornea and lens together have to somehow bend all incoming light at the right angle to make it focus on the retina, the eye’s "camera film". When the cornea bends the light too much to start with, the lens must adjust for that if we are to see clearly at all distances.

The lens adjusts by its ability to accommodate. Tiny muscles attached to the lens pull on it or relax and let it go. This makes it more sharply curved, or flatter. This happens automatically as we look from our book, for instance, to a tree across the road.

When light is traveling to the eye from your book, it needs to be bent at a steeper angle than light traveling from the tree. So the lens can correct the cornea's over-refraction and allow you to read your book, because less correction is required. But it can’t correct the over-refraction of light coming from the tree. The tree looks blurry because its light is being focused in front of the retina.

This is why reshaping the cornea corrects nearsightedness. The too-steep cornea is made slightly flatter, so that it doesn't over-refract. In our Clearview Eye and Laser Medical Center here in San Diego, California, we offer three specific ways to reshape the cornea and eliminate your myopia: LASIK, PRK, and IntraLase.

• LASIK
• PRK
• IntraLase
• Presbyopia
• Implantable Contact Lenses
• Intacs
• Cataracts
• BOTOX®

Previous Posts

• Modern Eye Surgery
• Bladeless LASIK – What’s all the Flap About?
• What is the Cornea?
• Cataract Symptoms
• Farsightedness vs. Presbyopia
• Farsightedness
• The San Diego Fires and Providing Eye Care
• Lasers Used for Vision Correction
• The Safety of IntraLase
• Toss Those Reading Glasses