Well, that's the the problem really. Many fairly common items make pretty deadly weapons if used as such. Things like skillets, hammers, chainsaws, cars, or even bricks or icepicks can be used as lethal weapons if you choose to do so.
Something like a dazzler has no other realsitic purpose than to flashblind someone.
This can make a significant difference in some jurisdictions: using weapon of oppurtunity often is less of a problem than using a weapon that was kept for that purpose.
Sometimes it does not really matter what the actual weapon is, a weapon of oppurtiny can be anything you have laying around to be used for some other realistic purpose. Perhaps a big maglite, or a meat cleaver knive, or a hammer, or even a chainsaw if someone invades your property after you've been cutting hedges.
I think lasers should be considered weapons of opportunity in most cases, unless specifically built to assault like dazzlers. Also they are not really that effective since you have to blind both eyes in an attacker, which is pretty hard to do quickly with something that outputs a beam about a centimetre wide at engagement distance.
One thing you could do is put a 'class IV laser in operation' warning sticker on your front door or property gate, ensuring that anyone breaking in or invading actually should have known doing so posed a severe health risk.
