Question:
My SO has to go for a field vision test on Monday for the possible diagnosis
of glaucoma. Could someone please tell me what this test is all about.
Answer:
The standard field test is a relatively straightforward test that is
designed to find any blind spots in the retina (the light-sensitive back of
the eye).
The patient sits with one eye covered, with his chin in a comfortable chin
rest. In front of the face is a hemispherical screen, about three feet in
diameter. The patient keeps the eye focussed on a point in the center.
Then, a small spot of light is projected somewhere randomly onto the
screen. If the patient sees this, he presses a button. Then, another spot
is selected and the test is repeated. And so on.
It takes about 15 minutes of this testing for each eye. It gets tedious,
but is a very important test, since it identifies whether any eye damage
has ocurred that is sufficient to reduce vision in any part of the retina.
Since glaucoma proceeds very slowly and eye damage occurs first in the
peripheral part of the retina, a patient typically doesn't notice any
changes in vision until a significant portion of the eye is damaged.
Bottom line: The field test is very easy to take (a bit tedious and
boring). It is a very important test to establish whether any eye damage
has occurred.
