Endangering lives should carry the stiffest possible sentence.
Prison sentences are a waste of taxpayers' money. I wonder what would happen to people like these in Iran or Saudi? Hands chopped off, lasers shone at them to make them go blind, a severe beating? Brutal and barbaric, but effective. We can't sink to those levels but there has to be a middle path such as really unpleasant and tough manual labour, for example, chain gangs, and total deprivation of all privileges for the duration.
You can't ban the sale of laser pointers, as is suggested, it just places the distribution of them into the hands of profiteeers and criminals and makes it harder for people who need them for legitimate usage to get them.