Board Thread:Theories and Speculation/@comment-25132842-20180312025951/@comment-4974066-20180321012737

I dont think blindness only happens when using Susanoo, but I do think using Susanoo makes blindness happen faster. It's just the general use of the MS deteriorates the vision, and much like how every MS is different with varying capacities (such as the strength of one jutsu between 2 users), perhaps the rate of blindness also varies from person to person.