INTRODUCTION
Refractive or Laser Eye Surgery (LES) is a laser reshaping of cornea thus changing its focusing power (1). For patients with moderate refractive errors this ambulatory procedure is a quick way to get free of glasses or contact lenses. The cost of LES can vary widely but it is rarely under $1,000 per eye (2).
REFRACTIVE ERRORS
Light from observed object penetrates through the cornea, lens and viscose liquid of eye globe, refracts and focuses on retina as an image. In farsightedness (hyperopia) where the eye globe is too long, light focuses in the front of retina and detected image will be blurred. In nearsightedness (myopia), eye globe is too short and light focuses behind the retina. In presbyopia (farsightedness of the aged) the lens becomes rigid and cannot refract light efficiently, so light from near objects will focus behind the retina again. In astygmatism blurred vision is caused by irregularities in corneal or lens shape. (3)
