Repeated thromboembolic events in women taking birth control pills. Now, an 18-year-old woman who was taking a contraceptive (desogestrel) for a few months suffered sudden loss of vision in her left eye. She was diagnosed with central retinal vein occlusion in the affected eye. Laboratory tests performed before commencing the drug were normal. After stopping desogestrel for one month, she recovered her vision (BMJ 2014; 349: g4499).