Fifty-two elderly glaucomatous patients, without a history of asthma or obstructive airways disease, who were using topical timolol for control of intraocular pressure were recruited. Their topical therapy was changed to either betaxolol or pilocarpine. The change was associated with improvement in mean peak flow from 278 l/min to 328 l/min (t = 5.73, p < 0.001), mean FEV1 from 1.66 l to 1.85 l (t = 7.09, p < 0.001) and mean FVC from 2.40 l to 2.64 l (t = 5.07, p < 0.001). Change to either betaxolol or pilocarpine was associated with improved lung function tests. Lung function tests in a control group of 20 showed no significant changes. Both drugs maintained control of intraocular pressure but betaxolol had fewer ocular side effects.