It would be trivially easy to manufacture a laser weapon that burns out your target's retinas; that kind of thing could fit on the bottom rail of a standard assault rifle. The problem is that even DEVELOPING such a weapon constitutes a minor war crime.
There has been some work done on creating a stunning weapon that uses low power lasers to ionize the air, and fire a current thru that ionized path, sort of what lightning does, but on a smaller scale.
Basically a wireless taser system. I know they had suitcase sized ones. I don't know if they have been able to scale down the technology yet.
This would be a promising first step towards "Phaser like" weapons.