Find one of his favorite things, be it a toy or snack and move it across his field of vision; try to see if you can get him to visually track it (i.e. S eyes follow the object).
These could also be indicators. Either way the best thing to do is take him to the vet.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.