CORRECTING
YOUR VISION WITH LASIK
|
Your
cornea takes the light that enters your eye
and focuses it onto the retina (the back of
the eye). Problems with the shape of the cornea
can keep you from seeing clearly. During your
LASIK, special instruments reshape the cornea.
This lets the cornea focus light better so
your vision is closer to normal. |
|
Myopia
With myopia, the curve of the cornea is too steep.
This makes the distance between the cornea
and the retina too long. Light rays from
distant objects focus in front of the retina,
making them look blurry. |
|
Hyperopia
With hyperopia, the curve of the cornea is too
flat. This makes the distance between the
cornea and the retina too short. Light
rays from the close objects focus behind
the retina, making them look blurry. |
|
Astigmatism
With astigmatism, the cornea is oval-shaped instead
of round, making both distant and near object
look distorted. |
|
LASIK
Instruments
The two main instruments used during the LASIK
are the excimer laser and the microkeratome.
The excimer laser produces a concentrated beam
of ultraviolet light that can be precisely focused.
The beam is so accurate that it can cut notches
in a human hair. And because the excimer laser
generates almost no heat, the surrounding tissue
is rarely damaged. The microkeratome can make
extremely thin and precise cuts. Its safe and
efficient use, though requires significant previous
surgical experience. It is used to separate the
surface layers of your cornea during the LASIK
procedure. |
