Learning each variation of braille code is like
learning a different language. Most people learn
the one or two variations they are most likely to
use. People whose vision is intact also can learn
braille, and should if they have regular interac-
tions with people who are blind. Many communi-
ties have schools and consultants who teach
braille as well as libraries that provide braille pub-
lications. Most public signage in the United States
includes braille translations.
See also VISION IMPAIRMENT.
bullous keratopathy Swelling (edema) and blis-
tering of the CORNEA. Bullous keratopathy most
commonly develops as a complication following
CATARACT EXTRACTION AND LENS REPLACEMENTor other
surgery on the EYE, though it also may develop as
a consequence of chronic irritation such as might
occur with DRY EYE SYNDROME.
The healthy cornea is about 75 percent water.
One function of the cells that surround the cornea
is to maintain this fluid balance. Irritation and
trauma that damage these cells diminishes their
ability to function, and the cornea retains more
water. The swelling stretches the surface of the
cornea, pushing the cornea into closer contact
with the eyelid and resulting in further irritation.
Bullae, or blisters, develop as the cornea’s attempt
to relieve the discomfort, much as blisters develop
on the feet or hands in reaction to friction.
Early symptoms of bullous keratopathy are a
sensation of grittiness in the eye, blurred vision,
excessive tearing, and PHOTOPHOBIA(sensitivity to
light). When bullae form, and especially when
they rupture, the PAINoften is severe. The oph-
thalmologist can diagnose bullous keratopathy
using SLIT LAMP EXAMINATIONof the cornea, a pain-
less procedure that combines an intense light
focused in a slit with magnification through a
ophthalmologic microscope. Eye drops or oint-
ment with a higher saline concentration than
tears helps draw fluid out of the cornea, reducing
the swelling. Soft contact lenses, which absorb
fluid from the eye and shield the cornea from con-
tact with the eyelid, relieve discomfort for many
people. Bullous keratopathy tends to be chronic,
and over time may result in damage to the cornea
that requires the cornea’s surgical removal (kera-
totomy) or CORNEAL TRANSPLANTATION.
See also BLISTER; KERATITIS; UVEITIS.76 The Eyes