Yechiel Michel Epstein,
Translation:Arukh ha-Shulchan…
“ Interestingly, though one blind in one eye cannot inspect plagues, since the verse specifies a 'full and complete visual' of the plague, he can be a judge, as the visual seen by one eye is no worse than trying to see a person at night, and the Torah does specifically permit issuing a final ruling at night, as explained in chapter 5. To sum up: one who can see with only one eye is perfectly valid to serve as judge from the beginning of a case through its final ruling, for if he could only issue a final ruling, how would he reach that point without first deliberating the entire case? ”
