I need some help figuring out how many lines someone's vision changed. I get that a change from 20/25 to 20/30 represents a drop by one line etc. I'm struggling with changes in between or beyond the graduations in the snellen chart, say 20/100 to 20/150, or 20/150 to 20/800.
I'll really appreciate your help, and yes i'm searched around. 🙂
I'll really appreciate your help, and yes i'm searched around. 🙂