UVB Light
There is a close relation between sunlight and skin care. Premature aging and skin cancer are two man conditions due to sun light.
Sun light is composed of different type of rays. These light are differentiate from each other on the basis of their wave length.
Today most malicious rays present in sunlight is uvb light and uva radiation.
Both these damage genome and but in different ways, uvb damage DNA directly whereas uva indirectly.
Why today the issue about uvb and uva are more high lighted as compare to the past.
Answer is simple one, due to the decrease in the thickness of ozone layer.
UVB light
These rays poses wave length ranger from 280nm to 315nm. Due to the shorter wave length these have higher frequency and highly energetic rays.
These are the tanning radiations of sun.
It does not penetrate deeper into skin and affect epidermis (outer layer of skin).
When uvb light penetrate into skin it turns into energy. This is the reason that it causes tanning and when sun light contain sufficient amount of uvb light it causes burning in skin.
The intensity of uvb light is not stable and vary with seasons and time. Its strength is on its peak at extreme noon hours of summer.
UVB Treatment
UVB light is not only hazardous to health but use in several medical therapies for the cure of different disease and conditions.
It is specially used for the treatment of chronic skin conditions like vitiligo, psoriasis and eczema etc.
Vitiligo is a loss of pigmentation of skin. In treatment of vitiligo uvb treatment is used to enhance the pigmentation of skin.
In psoriasis growth and die cycle time of skin cells decreases to about 6 days. These dead cells instead of leaving skin, stuck up the skin surface. And an inflammation developed in skin. UVB is an effective treatment of skin and slow down the rapid growth of skin cells.
UVA Light
It is less hazardous as compare to uvb rays. Lies between wave length ranges 315nm to 400nm. Its strength in sunlight no longer remains variable. It causes brownish shade of skin when exposed to uva light. It is due to the uva that our skin becomes brown when exposed to uva light. Its energy and frequency is lower as compare to the uvb light. It is familiar regarding pre mature aging.
PUVA Treatment
PUVA treatment is rapidly being popular for many skin diseases. In this mode of treatment first affected skin is sensitized and then exposed to uva radiations.
