Common Vision Problems (Refractive Errors)
Trouble seeing close objects, distant object or both are common vision problems, called refractive errors. They can almost always be corrected with glasses or contact lenses. In some cases laser, refractive surgery (Customvue Lasik, Lasik or PRK) may be used to correct your vision. This surgery changes the shape of the cornea. This reduces your need for glasses or contacts.
Nearsightedness is called myopia. If you are nearsighted, distant objects look blurry. But you can see close objects clearly. If you are nearsighted the cornea and the retina are too far apart. Sometimes, the cornea is also too curved. This makes light rays from distant objects focus in front of the retina. These objects then look blurry.
Farsightedness is also called hyperopia. If you are farsighted, close objects look blurry. If you are severely farsighted, distant objects may also look blurry. The cornea and the retina are too close together if your are farsighted. Sometimes, the cornea is also tooflat. This makes light rays from close objects focus behind the retina. These objects then look blurry.
If you have an uneven cornea, you have astigmatism. Both close and distant objects look blurry. With astigmatism, you are often also nearsighted or farsighted. If the curve of the corena is uneven, light rays cannot focus on just one point on the retina. Instead, they focus on two or more points, either in front of or behind the retina. This makes close and distant objects look blurry.
Presbyopia is the loss of close-up focusing. Normally, the lens in the eye changes shape to focus light directly onto the retina (back of the eye.) But with age, the lens hardens and cannot change its shape as easily. It then cannot focus clearly on close objects. This makes them look blurry. Difficulty seeing things close up, such as small print, using tools, threading a needle, etc. are symptoms of presbyopia. The first sign may be a tired feeling when you look at something close up. Presbyopia most often starts when you are 40 to 45 years old. It slowly gets worse until you are about 60 to 65. Presbyopia is most often corrected by wearing glasses or contact lenses. New technology can correct presbyopia during cataract surgery. New technology implants, such as the acrySof ReSTOR implant, are designed to improve your vision to see near, far, and everything in-between.