Here is a frameless shower door that I installed, the door that it replaced is pictured next to it.
This custom shower never had a door or curtain, the theory was that it was big enough and the water was far enough away that it wasn’t necessary. The new owner felt differently and wanted me to install something that kept the open feel of the shower, but reduced the water splashing out the opening. So this door is only 4 feet tall and about 2 feet wide.