I buy mine at dollar tree, I can see far away , but, cant' see a thing up close. I had what my Dr back in Maine called computer lenses and they were great but, I eventually grew out of them. Got another pair at Wal Mart and lost them at 300.00 a pair. that's when I decided dollar tree is good enough for now. But, I have to be careful and be checked because my mom had maccular degeneration and it is hereditary.What are monovision, never heard of them. I cant' use bi-focus they drive me crazy there is an in between area where I can't see any thing. Like reading a cookbook sitting on the shelf.