Webster's New World Medical Dictionary

eyelids, adult ptosis of the
Drooping of the
upper eyelids in adults, most commonly due to sep-
aration of the tendon of the lid-lifting (levator) mus-
cle from the eyelid. This may occur with age, after
cataract or other eye surgery, or due to an injury, an
eye tumor, or a complication of another disease that
involves the levator muscle or its nerve supply, such
as diabetes. If treatment is necessary, it is usually
surgical. Sometimes a small tuck in the lifting mus-
cle and eyelid can raise the lid sufficiently. More
severe ptosis requires reattachment and strengthen-
ing of the levator muscle.
eyelids, congenital ptosis of the
Drooping of
the upper eyelids at birth. Moderate or severe pto-
sis calls for surgical treatment to permit normal
vision development. If moderate or severe ptosis is
not corrected, amblyopia (“lazy eye”) may develop,
which can lead to permanently poor vision.
Congenital ptosis is often caused by poor develop-
ment of the levator muscle that lifts the eyelid.
Children with ptosis may tip their heads back into a
chin-up position to see underneath the eyelids or
raise their eyebrows in an attempt to lift up the lids.
Congenital ptosis rarely improves with time. Mild
ptosis usually does not require surgery early in life.
Treatment is usually surgery to tighten the levators.
If the levator is very weak, the lid can be attached or
suspended from under the eyebrow so that the fore-
head muscles can do the lifting. Even after surgery,
focusing problems can develop as the eyes grow and
change shape. All children with ptosis, whether they
have had surgery or not, should therefore regularly
visit ophthalmologists.
eyes, flashing lights in the
Spontaneous flash-
ing-light sensations in the eyes that can be caused by
a number of factors. A sensation of flashing lights
can be caused when the vitreous humor (the clear,
jelly-like substance that fills the middle of the eye)
shrinks and tugs on the retina. These flashes of light
can appear off and on for several weeks or months.
With age, flashes become increasingly common.
Flashes usually do not reflect a serious problem.
However, if one notices the sudden appearance of
light flashes or a sudden increase in flashing lights,
one should see an ophthalmologist immediately to
see whether the retina has been torn or whether
there is another cause. Flashes of light that appear
as jagged lines or “heat waves” in both eyes, often
lasting 10 to 20 minutes, are different from these
benign flashes. They are usually caused by migraine,
a spasm of blood vessels in the brain. These jagged
lines can also occur without a headache, in which
case they are termed ophthalmic migraine or
migraine without headache. Treatment may or may
not be necessary depending on the cause.