The Sun emits UV rays (radiation) that penetrate the earth’s atmosphere and is most often absorbed by our skin. There are two types of UV rays UVA and UVB. Overexposure to ultraviolet (UV) radiation from the sun can cause significant damage to your skin. UVB affects the outer Dermal layer of the skin while UVA penetrates deep into the epidermal layer of the skin where it can damage collagen, which is the protein that holds your skin together firmly and smoothly. UVA breaks down the collagen structure which results in wrinkles. Once collagen is damaged, it cannot re-build itself. Up to 80% of skin aging is caused by the sun.
Texture Changes caused by the sun
UV exposure causes thickening and thinning of the skin. Thick skin is found in coarse wrinkle especially on the back of the neck that do not disappear when the skin is stretched.
A condition called solar elastosis is seen as thickened coarse wrinkling and yellow discoloration of the skin. While a common effect of exposure to the sun is seen as thinning of the skin causing fine wrinkles, easy bruising and skin tearing.
Freckles/Sun Spots Pigment Changes Caused by the sun
The most noticeable sun-induced pigment change is a freckle or solar lentigo. Light-skinned people tend to
freckle more noticeably. A freckle is caused when the melanin-producing cell, or melanocyte, is damaged causing
it to get bigger. Large freckles, also known as age spots or liver spots, can be seen on the backs of the hands,
chest, shoulders, arms, and upper back. These are not actually age related but sun-damage related. UV exposure
can also cause white spots especially on the legs, but also on the backs of the hands and arms, as melanocytes.are destroyed.
Freckles and sun spots are signs of skin damage and develop as a result of too much sun exposure.
Freckles and sun spots are frequently found on face, legs and back of hands. Individuals who sunbathe regularly may develop freckles and sun spots all over their skin.
Blood Vessel Changes caused by the Sun
UV radiation causes the walls of blood vessels to become thinner leading to bruising with only minor trauma in
sun-exposed areas. For example, most of the bruising that occurs on sun-damaged skin occurs on the backs of
the hands and forearms not on the inside of the upper arm or even the inside of the forearm. The sun also causes the appearance of telangiectasias, tiny blood vessels, in the skin especially on the face.
Skin Bumps caused by the Sun
UV radiation causes an increased number of moles in sun-exposed areas. Sun exposure also causes precancerous
lesions called actinic keratoses that develop especially on the face, ears, and backs of the hands. The are small
crusty bumps that can often be felt better than they can be seen. Actinic keratoses are felt to be premalignant
lesions because 1 in 100 cases per year will develop into squamous cell carcinoma. UV exposure also
causes seborrheic keratoses, which are warty looking lesions that appear to be "stuck on" the skin. In contrast to
actinic keratoses, seborrheic keratoses do not become cancerous.
Eye Damage caused by the Sun
Ultraviolet radiation harms more than just your skin. Too much unfiltered sunlight can harm your eyes by
damaging the lens and even the retina.
Overexposure to the sun’s UV rays can damage the lens of the eye and increase your risk of developing cataracts.
Cataracts occur when the lens of the eye becomes cloudy, rendering all images blurry and out of focus.
Cataracts are the leading cause of blindness.
Retinal damage - Macular Degeneration caused by the Sun
Prolonged exposure to UV radiation can damage the retina (the sensitive lining of the eye used for sight).
Macular degeneration occurs when the macula (an area in the retina) is damaged, thus causing loss of central vision.
While studies have yet to prove what causes macular degeneration, it is possible that overexposure to the sun’s UV light may be a contributing factor.
Most forms of retinal damage are irreversible.
Snowblindness caused by the Sun
Did you know your eyeballs can actually get sunburned?
If you spend a lot of time outdoors in the snow on a bright sunny day without eye protection you can experience a condition called snowblindness that may leave you temporarily blind and in extreme pain.
Snowblindness occurs when the surface of the cornea gets burned.
Overexposure to the sun’s UV rays results in a painful sunburn. UV rays penetrate deep into the layers of your skin and kill living skin cells.
In response to this trauma, your body’s immune system increases blood flow into the damaged area so white blood cells can remove the dead skin cells. This blood flow is what causes your sunburned skin to become warm and red.
There is substantial evidence that sunburns can lead to DNA damage. Repeated sunburns dramatically increase your risk of developing skin cancer because of this damage to your DNA.