The NatureZap series of weed-killing wands eliminates pests of the chlorophyll persuasion without the use of harmful chemicals, or harmful bends and twists of your lumbar spine. NatureZap combines a cocktail of Infrared and UV light that, when applied to an unwanted infiltrator, creates heat to cut off its roots' water supply, and penetrates the ground to disrupt root function.
NatureZap affects only the plants you hover it over, and you don't have to worry about "over zapping," traits that are both a perk and a shortcoming of the product. On the upshot, use of the light wands is completely safe for people and wildlife; they leave no residue and no odor, and won't kill off the stuff you want in your yard or garden. But. Some buyers have complained that the area NatureZap covers per attack makes it tedious to use if you have a lot of weeds to take down, especially since, they report, you need to apply the beam for 15 to 30 seconds at each location.
Overall, NatureZap sounds like a better solution for weeds growing up through pavers and sidewalks, or the odd weed here and there, than it does for yards and garden beds full of them. Unless, I guess the weeder is retired and has nothing better to do than point-and-beam all day, in which case a NatureZap could also make a fine gift for your dad.