For this telescope, the lenses are a concave convex (one side curved out and the other curved in) and a plano concave (one flat side and one side curved in). The plano concave lens is used as the eyepiece with the plano (flat) side facing the eye.
If kidney function begins to decline, BUN and creatinine rise. A normal creatinine depends on muscle mass and age. In general, a normal creatine is 0.5 to 1.2 milligrams per deciliter (mg/dL). A normal BUN is 7 to 20 mg/dL.
Normal levels of BUN are between 10 to 20 mg/dl for an adult and 5 to 18 mg/dl for a child. Normal creatinine levels are between .5 to 1.1 mg/dl for an adult female and .6 to 1.2 mg/dl for an adult male.