Eye surgery tool (5)
I believe the answer is:
laser
'eye surgery tool' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for laser that I've seen before include "Light amplification by stimulated emission of radiation" , "Optical device producing an intense beam of light" , "Coherent light beam" , "Device producing an intense beam of light or radiation" , "modern light industry" .)