There are many kinds of crazy contact lenses but the most popular are the ones that can be used during Halloween - that's when we dress up the most. If it's Halloween then being scary is essential. White coloured contact lenses give you the most scary look you can have and therefore are one of the most popular types of crazy contact lenses. The ones that cover the whole eye, including the pupil, give the impression that you don't have any eyes and people don't know where you're looking. That's creepy!