HOW SUN-LIGHT DAMAGES THE EYES

Although the eyelid is designed to protect the
eye, its skin is exceedingly thin and contains
many fragile tissues that may be injured by
UV light. Inside the eye, the lens and the
cornea, both transparent, filter UV rays, but
by doing so for many years, they may become
damaged. This is especially true for the lens,
which through years of UV absorption, turns
yellowish and cataractous. The lens is the eye's
transparent focusing mechanism, located
between the iris and the vitreous humor (the
clear, thick gel in the posterior compartment
of the eye that fills the space between the
lens and retina, giving the eye its form and
shape). The cornea, the transparent area in
front at the outer layer of the eye, admits
light and images to the retina. UV damage is
instrumental in causing:

Eyelid cancers: Skin cancers of
the eyelid, including basal cell
carcinoma (BCC) and squamous
cell carcinoma (SCC) as well as
melanoma , account for 5 to 10
percent of all skin cancers.
Most occur on the lower lid,
which receives the most sun
exposure. Basal cell carcinomas
make up about 90 percent and
squamous cell carcinomas 5
percent or more of all eyelid
cancers, while melanomas
account for about 1-2 percent. basal cell
carcinomas of the eyelid affect an estimated
16.9 men and 12.4 women per 100,000 people in
the U.S. each year, and while basal cell
carcinomas elsewhere on the body rarely
spread, eyelid basal cell carcinomas have a
significant risk of spreading to the eye itself
and surrounding areas, causing major damage
to the eye and disfigurement to the face.

Squamous cell carcinomas have a faster growth
rate and a greater potential to spread. Both of
these types of cancer are found mainly in
patients with a history of sun exposure.
Melanoma can spread rapidly in the eye area
and can prove lethal if not treated promptly.
Melanomas have been linked to a history of
intense, intermittent sun exposure and
sunburns.
When diagnosed and treated early, eyelid
cancers usually respond well to surgery and
follow-up care, with the eye and eyelid largely
retaining normal function. With reconstruction,
they generally remain cosmetically attractive.
But left untreated, they are extremely
dangerous and may even ultimately penetrate
the brain. Watch for these early warning signs:

》a lump or bump that frequently bleeds or does
not disappear
》persistent red eye or inflammation of the
eyelids that does not respond to medication
》newly acquired flat or elevated pigmented
lesions that have irregular borders and growth
》unexplained loss of eyelashes

If you have any of these warning signals,
consult a skin cancer specialist or
ophthalmologist, even if you feel no
discomfort.

 The sun does have some health 

benefits, here's some more reasons to get some more sunlight
 

Intraocular melanoma: Although rare, it is the
most common eye cancer in adults. It starts in
the uveal tract, the middle layer of the eye
containing the iris (the part of the eye
responsible for eye color) and the pupil, which
lies in the center of the iris. Symptoms may
include a dark spot on the iris, blurred vision,
or a change in the pupil's shape. Sometimes,
however, there are no symptoms.
Conjunctival cancers: Once rare, these cancers
have been rising rapidly in incidence in recent
years, based on NCI data. Research covering 10
percent of the U.S. population showed that
incidence among white men especially
increased - 295 percent over a 27-year period.
Conjunctival melanomas may be more common
in patients with atypical mole syndrome; these
patients have 100 or more moles, one or more
moles 8 mm (1/3 inch) or larger in diameter,
and one or more moles that are atypical. All
patients with cutaneous melanomas and/or
atypical moles should have yearly
ophthalmologic evaluations.
Cataracts: A progressive clouding and
yellowing of the crystalline lens, the eye's
focusing mechanism. At least 10 percent of
cataract cases are directly attributable to UV
exposure. In the U.S. alone, more than one
million operations to remove cataracts are
performed every year. Cataracts are the most
common cause of treatable blindness worldwide,
and UVB has been directly linked to cataracts.
Macular degeneration: Often referred to as
age-related, or senile, macular degeneration, it
is caused by damage to the retina over time.
The retina is the ocular membrane where
images are formed and transmitted to the
brain; the macula, the region of sharpest
vision near the center of the retina, is the
most likely area to be damaged. Macular
degeneration is one of the major causes of
vision loss in the U.S. for people over age 60.
While further research is required, some
studies point to UVA and HEV light as
potential causes of macular degeneration.
Benign growths of the conjunctiva: Problems
with the conjunctiva, the protective membrane
covering the outside of the eye and the inside
of the eyelids, usually develop later in life.
Pterygia, fleshy benign growths on the
conjunctiva that may ultimately interfere with
vision, may require surgical removal. These
unsightly growths most frequently occur in
areas where UV is intense year-round.
Keratitis, or corneal sunburn: Excessive
exposure to UV from the sun or tanning
machines can literally burn the cornea, the
eye's clear refracting surface that admits
light and images to the retina. UV-protective
lenses are therefore especially a must for
anyone who uses a tanning machine, as well as
for skiers or snowboarders , since UV is more
intense at high altitudes, and since snow
reflects back the sun's rays, so that they hit
your eyes a second time.
Virtually all of these UV-related eye
conditions can be found by an ophthalmologist
during a routine eye exam. Thus, it is important
to have a complete ophthalmologic exam,
including dilated funduscopy, on a yearly
basis.