Among the 11 affected eyes , the final study visual acuity was 20/40 or better in 4 eyes ( 36 % ) , 20/50 to 20/80 in 2 eyes ( 18 % ) , 20/100 to 20/160 in 3 eyes ( 27 % ) , and worse than 20/800 in 2 eyes ( 18 % ) .