How Does Laser Eye Surgery Improve Vision
If you’re considering having laser eye surgery, it helps to understand how the laser vision correction operation can improve your vision.
A laser is a device that creates a very special kind of light energy. The light can be of any color and can be invisible to the human eye.
The excimer laser used for the laser eye surgery procedure makes pulses of invisible ultra-violet light. Each pulse of light removes a microscopically thin layer from the cornea, changing the curvature of the cornea ever so slightly. During the laser eye treatment, a computer running specialized software determines the exact pattern of pulses needed to remove the right amount of corneal tissue.
Laser eye surgery
When using laser eye surgery to correct nearsightedness, the curvature of the cornea must be decreased – the cornea must be made flatter. Tissue is removed in a disc-shaped pattern. To correct farsightedness, the central portion of the cornea must be made steeper. This is accomplished by removing tissue in a doughnut-shaped pattern. To correct astigmatism, the cornea must be made more symmetrical.
The excimer laser pulses may be applied to the surface of the cornea, using the technique known as PRK laser eye surgery.
Alternatively, the excimer pulses may be applied to the cornea under a thin flap of tissue, using the technique known as LASIK eye surgery.
During laser eye surgery, only a very small amount of tissue is removed, usually less than the thickness of a hair. Laser vision correction procedures for mild focusing problems will only require small amounts of tissue removal.
To correct nearsighted-ness, farsightedness, and astigmatism, the laser eye surgery removes a small amount of tissue from the cornea, causing the shape of the cornea to change ever so slightly.
Severe focusing errors will require greater amounts of tissue removal. The total treatment usually takes less than one minute of actual laser time.
