What prevents clogged blood vessels, high blood pressure

How do the uv rays cause damage?   what exactly causes the skin to burn;   can you be more specific about this mechanism?   3. how do photosensitive medications increase a person's sensitivity to sunlight and therefore increase their risk of getting burned?     what kind of medications can increase photo-sensitivity, can you think of some examples?

You have weighed the likely outcomes of your decision to move in with your dad and have made a decision based on those outcomes what is an example of

What is the function of the retina?