This might be milli which are small clear bumps that are caused by a vuildup of dirt and oil. Most people don't exfoliate or properly wash their back since it is a hard to reach place. If you go to the doctor, he/she may use a lancet to retrieve them out. To avoid this, exfoliate and cleanse your back daily.
It could be a type of heat rash or allergic reaction to something such as a new detergent. Or it could be a form of back acne caused by sweat or shampoo/conditioner.
Sometimes those clear bumps can be pimples to dead skin. You can get it from just sweating too much. Just use a good exfoliator and a bath poof and that should work.
This could be an allergic reaction, if it is at all itchy. Otherwise, it may be due to skin oils, combined with the fact that the skin (dernis) of the back is thick, and the oil glands are deeper.
Well most likely the thing causeing small clear bumps on the back of your skin is an abrassion of some sort. Usually this can last anywere from a day to a life time depending on the cause. The best way to deal with such a problem is to wear clothing or use duct tape on the area affected.
Have you had a suburn or been in the sun lately. Small clear bumps could be the result of a sunburn that has blistered. If the blisters pop then you will most likely peel. Try putting on some lotion to keep from peeling if and when they do pop!