Common Problems : Refractive Problems (Difficulty Seeing)
Refractive eye problems refer to the inability of your eye to focus on the retina (at the back of your eye), resulting in myopia and/or hyperopia. Myopia (nearsightedness) refers to a condition when you can clearly see objects that are close to you, but cannot see distant objects clearly. Hyperopia (farsightedness) refers to a condition in which you can clearly see objects at a distance, but cannot clearly see objects close to you. Causes of refractive eye problems include astigmatism and presbyopia. Astigmatism is an irregularity in the overall shape of the eye or the curvature of the cornea (the clear outer coating of the eye). Presbyopia occurs when the lens of the eye is no longer able to change shape. This typically takes place around age forty. Treatments for refractive eye problems include glasses/contacts, Lasik surgery, and PRK surgery. (1) Glasses and contact lenses correct refractive errors by adding or subtracting focusing power to your cornea and lens. The power needed to focus images directly on your retina is measured in diopters. This measurement is also known as your eyeglass prescription. If you have myopia, your cornea and lens have too much focusing power, bending light rays to meet at a point in front of the retina. Glasses and contacts compensate for this condition by subtracting power from the eye"s natural focus and allowing light rays to focus further back on the retina. If you have myopia, your prescription will be negative, for example, -4.25 diopters. If you have hyperopia, glasses and contacts add focusing power, causing light rays to bend more as they enter the eye. This process moves the focal point back to the retina, allowing for clear vision. If you have hyperopia, your prescription will be positive, for example, 4.25 diopters. (2) LASIK Surgery and PRK Surgery are procedures used to correct or reduce myopia with the goal of reducing or eliminating dependency on glasses or contact lenses. For more details about these procedures at NC Eye, Ear, Nose & Throat, click on the following: |
