They are different from regular glasses.
Mine are the linesless (which I love) and have a rx on the bottom and clear (non rx) on the top. Some have rx in both.

You will notice a fuzzyness in the middle and will have to tilt up/down your head so slightly to adjust to see. They will show you where to hold things to read so you dont have that "fuzzy" problem. This tilting at first is very common and you'll adjust. Kinda like people who are wearing contacts for the first time, they blink all the time.

I've worn bifocals for over 20 plus years and love them. I dont like the line bifocals. Only time I have problems is on the computer because of where the location of my monitor.