Answer:
safety, cost, and consumer testing.
Those things are so silly. i always used to put :going for a jog; exercising for 60 minutes every day; and cleaning around the house. and just say how your going to do those things. you can really put anything you want.
Technically, all of these can cause double vision and other vision problems.
I'm not really sure what "less responsive" indicates, because it can mean a broad spectrum of symptoms. However, I would answer this with alcohol because it causes your eye muscles to weaken and can include symptoms like involuntary twitching.
Sorry I couldn't provide you with a definite answer, but I hope I was able to help :)
