They come with about five different lenses of varying strength and a very handy head torch built in which does actually make a big difference. The benefit I have noticed over painting under the magnifying lamp thingy is that your brush is a lot freer and doesn't keep bashing into the lamp. It's very early days at the moment but the difference is huge, my eyes have been opened so to speak.
Since making my purchase I have noticed other brands on Amazon going for much less, always the way.
"More machine now than man, twisted and evil..."