I wonder if these optics were the cause of the Soviet tanks having such lopsided casualties in various tank battles, perhaps impacting their combat range.
Edited.
Not really.
http://www.panzer-war.com/page37.html
goes into the sights of different countries.
Now the USSR had their main optic plant lost in the invasion, so their secondary plants were not as good as the plant that was setup with German assistance/licenses
before the war, but quality picked up in 1943
The big problem was lack of decent visibility around the tank, a good optic still gives a tiny view of the World.
periscopes and vision blocks were really poor, and the resulting lack of situational awareness is what got them killed.