EYE, FOREIGN BODY IN
reflex is protective and helps to spread
the tear film evenly over the cornea to
enable clear vision.
to replace an
that has been removed. It is worn
for cosmetic reasons. Some movement
of the artificial eye may be achieved by
attaching the muscles that normally
move the eye to the remaining conjunc-
tival membrane (see
or to a
plastic implant in the eye socket.
eye, disorders of
are minor, but some can cause loss of
vision unless treated. (See also
is sometimes present at birth.
Rarely, babies are born with
affect the eye are
and developmental abnormalities of the
cornea and retina.
is the most common eye
infection and rarely affects vision.
or severe bacterial conjunctivitis
can impair vision. Corneal infections
can lead to blurred vision or corneal
if not treated early. Endoph-
thalmitis (infection within the eye) can
occur as a result of eye injury or infec-
tion elsewhere in the body.
Narrowing, blockage or
of the blood vessels of the
cause partial or total loss of vision.
the most common cancerous tumour of
is a cancerous
tumour of the retina that most com-
monly affects children.
larly of vitamin A) can affect the eye.
This may lead to
may be caused by infection or
of the retina is
common in the elderly, as is
, in which the pressure in-
side the eyeball becomes raised, can
lead to permanent loss of vision. In
, the retina lifts away
from the underlying layer of the eye.
Ametropia is a general term for any
focusing error, such as
the progressive loss with age of the
ability to focus at close range.
is often due to squint.
Medication in solution used
or to aid in diag-
nosis. Examples of drugs given in this
, and drugs
used to dilate or constrict the pupil.
eye, examination of
An inspection of
the structures of the
, either as part
or to make a diagnosis
An eye examination usually begins
with inspection of the external appear-
ance of the eyes, lids, and surrounding
skin. A check of eye movements is usu-
ally performed and the examiner looks
. A check of the
each eye using a
testing (using lenses of dif-
ferent strengths) may be performed to
determine what glasses or contact lens-
es, if any, may be needed. A test of the
may be performed, espe-
cially in suspected cases of
may be checked because loss of colour
perception is an indication of certain
disorders of the
check for abrasions or ulcers, the
may be stained with
an essential test for glaucoma.
is an instrument
used to examine the inside of the eye,
particularly the retina. The slit-lamp
microscope, with its illumination and
lens magnification, allows examination
of the conjunctiva, cornea, front cham-
ber of the eye,
. For a full
view of the lens and the structures
behind it, the
must be widely
eye, foreign body in
Any material on
the surface of the
or under the lid,
or an object that penetrates the eyeball.
A foreign body may cause irritation,
redness, increased tear production, and
In some cases, a foreign
body left in the eye may cause a reac-
tion that results in permanent loss of
sight in both eyes.
Foreign bodies on or in the
can usually be flushed out with