VISION CARE
Learn about various eye disorders and diseases and different laser eye surgery procedures. Vision problems can be caused by structural defects, infections, injuries, and various diseases. Ophthalmology is the medical specialty that deals with all issues concerning the function of the eyes, and is administered by a medical doctor specializing in ophthalmology. If a person is found to have a serious eye disorder, he or she will usually be referred to an ophthalmologist. Optometry is primarily concerned with visual acuity and detecting some disorders of the eye, such as glaucoma. However, optometrists do not have a medical doctorate (meaning they did not go to medical school). Optometrists receive their graduate degrees from Optometry schools. Vision Care relating to visual acuity is usually not covered well, if at all, by most major health insurance companies. Supplemental vision insurance is usually needed. Laser Eye Surgery to correct problems of visual acuity is rarely covered by any type of medical insurance (major medical or supplemental). Vision care related to eye disease or injuries is usually covered under most major medical insurance policies.
Vision Overview
The cornea is a part of the eye that helps focus light to create an image on the retina. It works in much the same way that the lens of a camera focuses light to create an image on film. The bending and focusing of light is also known as refraction. Usually the shape of the cornea and the eye are not perfect and the image on the retina is out-of-focus (blurred) or distorted. These imperfections in the focusing power of the eye are called refractive errors.
Three Primary Types of Refractive Errors
Myopia, hyperopia and astigmatism:
- Myopia, or nearsightedness - A person has more difficulty seeing distant objects as clearly as near objects.
- Hyperopia, or farsightedness - A person has more difficulty seeing near objects as clearly as distant objects.
- Astigmatism - A distortion of the image on the retina caused by irregularities in the cornea or lens of the eye. Combinations of myopia and astigmatism or hyperopia and astigmatism are common. Glasses or contact lenses are designed to compensate for the eye's imperfections. Surgical procedures aimed at improving the focusing power of the eye are called refractive surgery. In LASIK surgery, precise and controlled removal of corneal tissue by a special laser reshapes the cornea changing its focusing power.
LASIK Laser Eye Surgery
Learn about LASIK, the laser vision correction procedure that has helped millions of vision patients achieve freedom from contact lenses or eye glasses. Learn about other Vision Care topics. Learn about laser eye surgery and what it accomplishes. Learn about the other types of LASIK laser eye surgery procedures such as Bladeless All Laser LASIK, Custom LASIK, Epi-LASIK and LASEK. You can also find local LASIK surgeons.
Radial Keratotomy or RK and Photorefractive Keratectomy or PRK, are other refractive surgeries used to reshape the cornea. In RK, a very sharp knife is used to cut slits in the cornea changing its shape. RK is seldom, if at all, used these days. PRK was the first surgical procedure developed to reshape the cornea, by sculpting, using a laser. Later, LASIK was developed. The same type of laser is used for LASIK and PRK. Often the exact same laser is used for the two types of surgery. The major difference between the two surgeries is the way that the stroma, the middle layer of the cornea, is exposed before it is vaporized with the laser.
In PRK, the top layer of the cornea, called the epithelium, is scraped away to expose the stromal layer underneath. In LASIK, a flap is cut in the stromal layer and the flap is folded back.
FDA Regulation
In the United States, the Food and Drug Administration (FDA) regulates the sale of medical devices such as the lasers used for LASIK. Before a medical device can be legally sold in the U.S., the person or company that wants to sell the device must seek approval from the FDA. To gain approval, they must present evidence that the device is reasonably safe and effective for a particular use, the "indication." Once the FDA has approved a medical device, a doctor may decide to use that device for other indications if the doctor feels it is in the best interest of a patient. The use of an approved device for other than its FDA-approved indication is called "off-label use." The FDA does not regulate the practice of medicine.