Hello all, I am a contact lens tech, so I decided to come here for some spec advice.
My Mom has had numerous problems with progressive lenses. After switching materials, and numerous other attempts from the optician she is working with, she has decided to go to bifocals or trifocals. So her question is, when switching from a progressive lens, which would be the best for her to switch to, bifocal or trifocal? Could you give me the pro's and con's of each? I would like give her as much info as possible. Thanks!