"An antiglaucoma composition in unit dosage form comprising a carrier and as active component from 0.25%-0.5% of a hexahydrodibenzo (a, f) quinolizine in a collyre in racemic or optically active form of general formula I: ##STR3## where r1 and R2 are H, Ch3, or CH3 CO; R3 and R4 are H or OH; R5, R6 and R7 are H, OH or CH3 O; X is a halogen, and pharmaceutically acceptable salts thereof-in an amount" . . . . .