8 letters · 11 points in Scrabble
noun (ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people
noun (optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point
originFrom a- (negative prefix) + Ancient Greek στίγμα (stígma, “mark, point”) + -ia.
Etymology from Wiktionary, CC BY-SA 3.0