Monday, January 30, 2012

Myopia

Myopia is a refractive defect of the eye in which collimated light produces image focus in front of the retina under conditions of accommodation. In simpler terms, myopia is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object.

Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses. It may also be corrected by refractive surgery, though there are cases of associated side effects. The corrective lenses have a negative optical power which compensates for the excessive positive diopters of the myopic eye. Myopia is partly hereditary.

Monday, December 12, 2011

Eye Vitamins

Eye vitamins and supplements
Taking eye vitamins can help our eyes stay healthy for a longer period of time. Vitamins for the eyes can also help prevent many diseases. Although we can obtain all the vitamins and minerals we need by eating certain foods, it is nearly impossible in the fast food controlled times to get a healthy meal with all the vitamins and minerals. That is where eye vitamins come in.

Choosing an eye vitamins
When choosing a brand of eye vitamins it is a good idea to compare vitamin and mineral composition compared to daily values and of course prices.

Wednesday, December 7, 2011

Introduction LASIK

The introduction of lasers in refractive surgeries stemmed from Rangaswamy Srinivasan's work. In 1980, Srinivasan, working at IBM Research Lab, discovered that an ultraviolet excimer laser could etch living tissue in a precise manner with no thermal damage to the surrounding area. He named the phenomenon Ablative Photodecomposition (APD).

The use of the excimer laser to ablate corneal tissue for the correction of optical errors, such as myopia, hyperopia, and astigmatism, was first suggested by Stephen Trokel, MD, of the Edward S. Harkness Eye Institute, Columbia University, New York.

LASIK History

The LASIK technique was first made possible by the Colombia-based Spanish ophthalmologist Jose Barraquer, who, around 1950 in his clinic in Bogotá, Colombia, developed the first microkeratome, and developed the technique used to cut thin flaps in the cornea and alter its shape, in a procedure he called keratomileusis. Barraquer also researched the question of how much of the cornea had to be left unaltered to provide stable long-term results.

Later technical and procedural developments included RK (Radial keratotomy), developed in the USSR in the 1970s by Svyatoslav Fyodorov, and PRK (photorefractive keratectomy), developed in 1983 at Columbia University by Dr. Steven Trokel, who in addition published an article in the American Journal of Ophthalmology in 1983 outlining the potential benefits of using the excimer laser patented in 1973 by Mani Lal Bhaumik in refractive surgeries. (RK is a procedure in which radial corneal cuts are made, typically using a micrometer diamond knife, and is completely different from LASIK).