Yes, GLASSES is a Scrabble word!

Letter values in Scrabble US: G 2, L 1, A 1, S 1, S 1, E 1, S 1.

Is it a valid word?

GLASSES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

optical instrument consisting of a frame that holds a pair of lenses for correcting defective vision
a brittle transparent solid with irregular atomic structure
a container for holding liquids while drinking
the quantity a glass will hold
a small refracting telescope
an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant
a mirror; usually a ladies' dressing mirror
glassware collectively

Also: drinking glass, field glass, methamphetamine hydrochloride, chicken feed, looking glass, glass in, glass over, glaze over.

Not playable in Scrabble US: DEOXYEPHEDRINE, SHABU.