Disadvantages
We do not know at this time if Viagra, Cialis, or Levitra causes NAION. NAION also happens in men who do not take these medicines. People who have a higher chance for NAION include those who:
* have heart disease
* over 50 years old
* have diabetes
* have high blood pressure
* have high cholesterol
* smoke
* have certain eye problems
FDA has approved new labels for Viagra, Cialis, and Levitra to include information on possible eyesight loss (NAION).