Great vision depends upon how well your cornea as well as lens focus light rays on the retina. Light rays should flex, or refract, to focus on the retina. The retina is the light-sensitive nerve layer that lines the back of the eye. It develops impulses from the light rays that are sent via the optic nerve to the brain.
Refractive mistakes are vision issues created generally by a cornea that is not formed perfectly or an eye that is longer or shorter than typical. The cornea is the clear component at the front of the eye. It flexes as well as focuses light waves. Refractive mistakes cause light from an item not to be focused on the retina. This creates a blurred picture. Refractive errors can occur in or else healthy and balanced eyes.
There are four types of refractive mistakes:
- Nearsightedness, or myopia. Close things appear sharp. But things distant are obscured. The eye is longer than typical from front to back. Or the cornea is curved too much. Images concentrate in front of the retina instead of on it.
- Farsightedness, or hyperopia. You can see remote things plainly. But items up close are blurred. The eye is shorter than typical. Or the cornea is too level. Pictures focus on the retina.
- Astigmatism. Items are blurred at any kind of range. The lens, cornea, or both are formed to ensure that photos aren’t concentrated sharply on the retina.
- Presbyopia. This is additionally known as the aging eye. The eye loses its ability to alter emphasis because of the all-natural aging procedure. This often happens between the ages of 40-50. Refractive surgical treatment can’t correct this problem. Surgical treatment can make range vision clear. However, it may make near vision worse.
Kinds of surgical treatment
Types of Eye surgery [ศัลยกรรมตา, which is the term in Thai] to correct refractive mistakes include:
- LASIK, or laser in-situ keratomileusis
- Photorefractive keratectomy, or PRK
- Radial keratotomy, or RK
- Astigmatic keratotomy, or AK
- Automated lamellar keratoplasty, or ALK
- Laser thermal keratoplasty, or LTK
- Conductive keratoplasty, or CK
- Intracorneal ring, or Intacs