Lasik stands for Laser-Assisted in Situ Keratomileusis, a type of refractive laser eye surgery with the aid of medical microscope performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. The procedure is preferred to photorefractive keratectomy or PRK, because it requires less time for the patient’s full recovery, and the patient feels less pain, overall. Many people all over the world today choose LASIK as an alternative to wearing corrective eyeglasses or contact lenses. Those with myopia see nearby objects clearly but distant objects appear to be somehow blurred. With myopia, the eyeball is too long, or the cornea is too steep, so images are focused in the vitreous inside the eye rather than on the retina at the back of the eye. The opposite defect of myopia is hyperopia. Hyperopia, also known as hypermetropia or colloquially as farsightedness, is a defect of vision caused by an imperfection in the eye which is often when the eyeball is too short or when the lens cannot become round enough, causing inability to focus on near objects, and in extreme cases causing a sufferer to be unable to focus on objects at any distance. As an object moves towards the eye, the eye must increase its power to keep the image on the retina. If the power of the cornea and lens is insufficient, as in hyperopia, the image will appear blurred. To some, it is referred to as farsightedness or long-sightedness this is where the cornea is too flat or the eye is too short.

As of the present times, ophthalmologists and optometrists most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses. It may also be corrected by refractive surgery with the aid of medical microscope, such as LASIK.  Astigmatism however is an affliction of the eye, where an erratically shaped cornea blurs vision. The cornea, as a substitute of being shaped like a sphere, is more oval-like and reduces the cornea’s ability to focus light. Astigmatism is a refractive error of the eye in which there is a difference in degree of refraction in different meridians for example the eye has different focal points in different planes. For example, the image may be clearly focused on the retina in the horizontal or sagittal plane, but not in front of the retina in the vertical or tangential plane. Astigmatism causes difficulties in seeing fine detail, and in some cases vertical lines or walls may appear to the one who has astigmatism to be leaning over juts like the tower of Pisa.

The effects of astigmatism of the eye can often be corrected by prosthetic lenses with a cylindrical lens, a lens that has different radii of curvature in different planes, contact lenses, or refractive surgery. Keratitis is a condition in which the eye’s cornea is inflamed according to these scientists whom have devoted a lot of time and effort on studying these conditions. Keratitis has numerous cause, one of which is an infection of a present or previous herpes simplex virus secondary to an upper respiratory infection, involving cold sores. Read the entire article