What effects does tadalafil have on vision?

Visual side effects associated with tadalafil are  rare, likely due to tadalafil’s low affinity for  PDE6. In the analysis of 11 integrated randomized,  double-blind, placebo-controlled trials  lasting 12 weeks [23], there were no reports of  ‘‘blue vision’’ among the 1464 men taking  tadalafil. In a long-term safety study involving  1173 men taking tadalafil for 18 to 24 months  [50], one episode of ‘‘blue vision’’ was reported.