The animation played when using the shield is bugged and obscures more vision than intended.

While I am not sure what led this to happen, I have found that leaving and rejoining the world does not seem to do anything. Furthermore, it seems that crouching while the shield is not in your off-hand plays no animation when I believe it should.

 

Update: It seems that restarting the game does not fix this issue.

 

Update Two: The bugged animation does not always play, although it does the majority of the time.