Normal visual sensation in the absence of complete visual perception is best illustrated by

prosopagnosia.

Explanation:

This condition will make people unable to recognize subjects or objects that we encountered everyday (such as not being able to recognize your own or your friends' faces). Usually, this condition occurs after we experience a damage in part of our brain that control reconsecration process. In united states, there are around 2.5% of people have  prosopagnosia.

answer; shared meaning;

answer; have joints that fail from excess by early the accumulated effects of unnoticed infections,all of these things are possible for a person born without the ability to feel pain;