Don't scratch your lens.
Photographers with expensive lenses having a filter attachment have a lens-protecting hack: A zero-density neutral filter. It's essentially a cheap protective transparent cover. Let the filter get scratched or dirty instead of the lens and replace it for cheap when it's too crummy to continue using.
Probably won't work with your digital camera. (But ours retracts and covers the lens when not in use...)
I found out about this filter hack while doing automation for a manufacturing plant: Colleague had done a vision system to automate some welding and the workers didn't like having the job automated. Company painted machinery a standard color (light green for the power tool stations) and when the millwrights painted these devices when they arrived at the plant they sprayed the whole camera, lens and all. After the first time this happened (requiring an expensive lens replaement and retweaking) the maker of the vision system did the neutral-filter hack. The workers painted the camera, the equipment manufacturer swapped the filter, ta-dah!