Many of the side-effects and contra-indications of sildenafil and other phosphodiesterase 5 (PDE 5) inhibitors for erectile dysfunction have become well known to doctors and pharmacists over the years. This study from the United States collected case reports of adverse ocular reactions from PDE 5 inhibitors from a large database.Among 200,000 patients using sildenafil, tadalafil, vardenafil and avanafil, the incidence of retinal detachment / retinal vascular occlusion and ischaemic optic neuropathy was nearly double as compared to the control group of non-users. In busy urology / andrology clinics, good communication is required and patients should be fully informed about these potential adverse effects. This will go a long way to avoid complaints and possible litigation. In renal failure with eGFR of less than 30ml/minute further caution is required and the starting dose of sildenafil should be 25mg.