Some of us have experienced problems with our vision over time and maybe considering vision correction options. Many are plain frustrated with the need to wear contacts or glasses. There are several options that can correct refractive issues such as astigmatism, presbyopia, hyperopia (farsightedness), and myopia (nearsightedness). Astigmatism is known as warped or distorted vision caused by the surface of the eye being irregular in shape, somewhat. The irregularity causes the eye to have various focal points that distort images.
Presbyopia is brought on by age and describes the condition in which the eye loses the ability to focus on near objects. Hyperopia is brought on when near objects are blurry and far objects are clear. The blurriness is caused by the eye being too short and/or the cornea being too flat for its focusing ability. Myopia occurs when near objects appear clear, but distant objects are blurry. The blurriness is caused by the eye being too short and/or the cornea being too flat for its focusing ability.
Artificial Lens Implants
Intraocular Lens Implants or IOLs are lens implants in the eye. Rather than placing the lens on the surface of the eye like with a contact lens, all IOLs involve inserting a lens inside the eye. Most lens implant procedures involve replacing an existing lens with a new one in order to improve vision. To help correct vision, there are several types of IOLs available. Types of IOLs are toric, multifocal implants, accommodating implants, monofocal implants, and phakic implants.
PRK (Photorefractive Keratectomy)
PRK involves using the Excimer laser to correct vision by reshaping the cornea. With PRK, the outer skin of the cornea (epithelium) is removed and a laser is applied to the surface. PRK can be used to correct low to high levels of farsightedness, nearsightedness, and astigmatism. This procedure is for those who want to eliminate or reduce using contacts or glasses, have large pupils, have no health issues concerning the eyes, corneas are too thin for LASIK and are older than 18 years of age.
Another popular way of correcting vision is by LASIK (laser in-situ keratomileusis) surgery. LASIK uses a laser to change the curvature of the cornea. This procedure removes tissue within the cornea by treating low to high levels of farsightedness, astigmatism, and nearsightedness. This procedure is for those who have no signs of cataracts or glaucoma, are older than 18 years of age, want to reduce or eliminate using contacts or glasses, eye prescription has been stable for at least one year, have no health issues concerning the eyes, and have no signs of glaucoma or cataracts.
Relatively new, LASEK combines elements of LASIK and PRK and may have some advantages over them. A flap of surface epithelium is loosened and moved aside using a diluted alcohol solution, instead of completely removing the epithelium. The laser treats the surface under the epithelium then returns the epithelial flap back to its original position.
LASEK uses the epithelium flap like a natural protective bandage which may improve healing. LASEK treats low to high levels of astigmatism, nearsightedness, and farsightedness by removing tissue within the cornea. LASEK is for those who do not want LASIK because it requires a microkeratome, have wide pupils, have corneas too thin for LASIK, want to reduce or eliminate using glasses or contacts, are older than 18 years of age, eye prescription has been stable for at least one year, and have no health issues with their eyes.
LTK (Laser Thermal Keratoplasty)
LTK, a non-contact laser procedure, eliminates or reduces the farsightedness and offers people who read small print with difficulty, the chance to read without the use of reading glasses or bifocals. LTK changes the shape of the cornea, making it steeper. The steeper curvature of the cornea increases focusing power and brings images on the retina into proper focus. This procedure is for those who want to eliminate or reduce using bifocals or reading glasses, are 40+ years of age, had good vision until they reached their forties, and have no health issues affecting their eyes.
Limbal Relaxing Incisions (LRI)
The thin area of the eye that connects the cornea and the sclera is the limbus. Low to moderate degrees of astigmatism are treated with limbal relaxing incisions (LRIs). Small relaxing incisions are made in the limbus by the surgeon, allowing the cornea to become more rounded after it heals. LRIs are placed on the steepest meridians at the very edge of the cornea.
Astigmatic Keratotomy (AK)
An outpatient surgical procedure, Astigmatic Keratotomy (AK), eliminates or reduces astigmatism. A cornea that is football-shaped, flat in one meridian and steep in the other, causes astigmatism. In order to correct this, the cornea has to be reshaped into a more spherical shape, similar to a basketball. During AK, microscopic incisions are placed in the steeper meridian of the cornea. These incisions decrease the degree of astigmatism by causing the cornea to assume a more spherical shape.