I took several Amsler Grid tests and I noticed that when I squint really hard, I can see the lines inside the dot in the middle. The dot is dark black but when I squint, the spot becomes transparent and I can see the intersection of the lines. Sometimes the lines are bent/broken but that only applies to the intersection inside the black dot but the lines around the spot are normal. Does anyone know what I am talking about and if it's normal?
Also, there was this one particular big grid and the spot was really big. When I looked at it, I see the dot shake. But that doesn't happen to other grids only that one.