Answer:

eyesight

Answer	Crossword Clue
EYESIGHT	Optometrist's concern
EYESIGHT	It improves when you have contacts
EYESIGHT	Common sense that Milton and Homer lacked

EYESIGHT	Vision
EYESIGHT	Ophthalmologist's concern
EYESIGHT	Vision.
EYESIGHT	It needs some perspective
EYESIGHT	It may improve if you have contacts