While erectile dysfunction (ED) medications such as sildenafil (Viagra) have completely changed the way impotence is treated, it should be pointed out that some men who take ED pills develop visual disturbances (usually in the form of blurred vision, impaired color vision, or a bluish haze). While these problems may be mild and temporary, they are reason enough for the FDA to say that pilots should not take ED pills within six hours of taking flight. ED pills have also been linked with “nonarteritic anterior ischemic optic neuropathy” (NAION), a poorly understood disorder that can cause blindness due to blocked blood flow to the optic nerve. Men with a history of NAION should not use ED pills. Eye care providers can easily screen patients who are concerned about this optic nerve anatomical risk.