My problem with Optivisors is that, like many other people, I have two eyes that see differently. One of them focuses at a different distance than the other. So both lenses of an Optivisor can't be in focus for me at the same time.
I use two solutions (neither completely satisfactory, but both far better than nothing). One is an LED magnifying lamp, like Don's. The other is a pair of prescription reading glasses, which I had the optician make for me at the same time he filled my bifocal prescription. Those glasses work well, but I remember with great nostalgia the days when (having been born nearsighted) I could see everything I needed to see on a model with no magnification at all.
Those were the days....
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.