I have no idea at all whether it really works, but I have to say I am pretty suspicious:
A) You only see red eye reflections from a predator (or any other animal) IF you are almost exactly in line with a light that's shining at the animal -- headlights of your car, flashlight you're holding, porch light over your head. Unless
animals commonly wander around shining headlights, flashlights, porchlights etc at each other,
they themselves should seldom be in circumstances to see each others' eye reflections.
and B) as already pointed out, animals that hang out around human habitation see LOTS of funny lights already, I suspect only the paranoidest predators are going to be deterred. And even then not necessarily for long -- look at how quickly 'pest' birds become accustomed to all the bird-scaring devices people put in gardens, once the birds realize that Nothing New Happens.
Mind, this is just theory, but still, I would not be the first one on my block to shell out money for this particular gadget
Pat