Answer: reticle

AnswerCrossword Clue
RETICLE

Grid in the eyepiece of an optical instrument

RETICLE

Network of fine lines for focusing telescopes.

RETICLE

Network of lines in the focus of an eyepiece.

RETICLE
Network, as in a gunsight.
RETICLE
Eyepiece grid
RETICLEOptical network
RETICLEEyepiece network
RETICLEOptical reference grid
RETICLEGrid on an eyepiece