You solve this problem by providing light in the chicken coop. The extra light stimulates the pituitary gland in chickens, which causes the gland to produce a hormone essential to egg laying. In humans, light affects the pituitary gland, as well, and one result is the production of MSH. A funny side-effect of all of this is that wearing sunglasses may make you more susceptible to sunburn!
If you are @Caucasian and you don't have a tan, then the cells in your skin are not primed with melanocytes, and they are therefore not protected from the sun's ultraviolet radiation. You become an easy target for sunburn if you spend too much time in the sun. As anyone who has a sunburn knows, sunburn leaves your skin red and extremely painful. In severe cases, the skin forms blisters. These responses are actually cellular damage caused from UV exposure. The body responds to the damage with increased bloodflow to the dermis' capillary bed in order to bring in cells to repair the damage. The extra blood in the capillaries causes the redness -- if you press on sunburned skin it will turn white and then return to red as the capillaries refill.
You can block or absorb UV with opaque creams like the white zinc oxide cream that you see lifeguards putting on their noses.
