Are all blue-eyed tortoise shell cats blind? My mother told me that all of them are. Are they?

No, that is in fact incorrect. Tortoise kitties are mostly females, and it's incredibly rare to find a male turtle (nickname for the cats). Though they are not always blind, it is common for turtles to have eye problems and eye infections. Tortoise Shells are known to have eye problems, and they require a great amount of care. Your mother may be thinking of white cats with blue eyes. White cats with blue eyes are also very hard to care for, as they often get very sunburnt because of their light coloured coats, and most white cats with blue eyes are in fact blind. They are also most of the time, deaf as well as blind. Although both breeds have eye problems and are hard to care for, they are both beautiful cats and would still make a great companion as a family pet.