"Is my penis smaller than average?" This is a question most men ask their partners at one point or another. Unfortunately, unless you're bigger than the norm (or dating a sociopath), you probably didn't receive a frank and honest answer.

The self-explanatory World Penis Data website attempts to provide a definitive answer. Here's the number you need to beat.

Whether you're on your first pair of glasses or your tenth, you may still be put off by phrases like "temple arms" and "lens height," especially if you're interested in shopping for your own frames. This visual guide shows you what all those terms mean so you can buy confidently.