It's summer! Even though in Jamaica we don't experience the four seasons, the effects of sunlight is more pronounced in the 'summer months' of July and August as we are more likely to spend more time outdoor with family and friends.

Sunlight is composed of many wavelengths and is grouped into the following three categories:

* UVC light ranges from 200-290 nanometers (nm). Almost all light in this range is filtered by the atmosphere.

* UVB light ranges from 280-320 nanometers and is called the burning region because it penetrates the top layer of the skin. This type of light causes acute skin damage and is immediately apparent (sunburn).

* UVA light is composed of wavelengths between 320-360 nanometers and penetrates deeper into the skin where it can cause chronic damage of cellular structure.

Excessive or chronic sun exposure can result in the following damages:

1) Uneven pigmentation on the face with brown patches called Melasma, or dark pigmentation around the eyes giving appearance of "raccoon eyes".

2) White spots on the lower legs and arms called age spots.

3) Wrinkling and sagging of the face, especially along the laugh lines, referred to as the mid-face drop.

4) Skin cancer, although rare in darker skin individuals, can and will occur with chronic sun exposure.

The impact of sunlight can easily be seen by comparing the difference in skin on the face to an area that is not exposed to constant sunlight such as the buttocks or inner arm. This skin appears smoother and less pigmented because it is less exposed to direct sunlight.

In order to protect yourself against the sun, I recommend a sunscreen lotion with a SPF factor of 55-100 be applied to your skin every morning, half-hour before sun exposure. The sunscreen lotion should be reapplied every 2 hours for more effective protection. A broad rim hat should be worn, when possible, along with a pair of dark glasses to protect the vulnerable eye area.

Next week I will be discussing the prevention and treatment of Melasma. Remember your sunblock!!

Dr Patricia Yap is a dermatologist at Apex Skin Care and Laser Center.