by TEMPLATED
If any one of your relative had any eye problems, particularly retinitis pigmentosa, taking this medicine might not be entirely risk-free for you, as you can experience a severe but really unusual negative side effects - vision reduction.
If you have a past of priapism (extended and unpleasant erection), taking Cialis may not be completely risk-free for you, as the same reaction might occur once more.

Your physician may give additional details.