In clinical studies involving over 1800 patients treated with AZOPT as monotherapy or adjunctive therapy to timolol maleate 5 mg/ ml, the most frequently reported treatment-related adverse events were: dysgeusia (5.8%) (bitter or unusual taste, see description below) and temporary blurred vision (5.8%) upon instillation, lasting from a few seconds to a few minutes (see also 4.7 Effects on ability to drive and use machines).