Pip-Boy medical enhancer
The Pip-Boy medical enhancer consists of a storage holodisk, microfilament cord, headgear, and an optical sensor that is placed over the user's left eye. When used, an optical flash transmits a dictionary of physician skills and know-how into the user's memory, permanently improving the user's Doctor skill by +10%.
This enhancer is probably one of the most obscure items in the entire game. To get it, the spectacles must be stolen from the Professor's radscorpion in Broken Hills and be brought to Renesco in New Reno.
For a reward, Renesco can be asked for money, a discount on his wares, or just let him keep them. If the reward is declined, there's an option to ask Renesco how the glasses are working out. Doing that 20 times will annoy him into throwing the medical enhancer.