Magic is perhaps a strong word LOL and they are not really nice but they were the best buy of the year in what regards yachting. I know that it seems odd but if you are more than 50 years old tel me how many times you had to take away your sunglasses and get another spectacles to see better some small detail in your plotter?
That's quite pissing specially for guys with a 100/100 vision and that now have to resource to a glasses with one or two dioptres to see fine details.
That's finished, I mean that stupid game of changing glasses and there is some magic in it. I bought them at a boat show in Croatia half believing that they would not really work in real conditions. They are normal polarized ones but with a small lent with dioptres on the right place and they really work effortlessly. I am so happy with them that I had to share it. They are really usefull, the gadget of the year!!!.
The brand is Australian:
http://barzoptics.com/polarised-sunglasses-with-bifocal-reader-lenses
Don't buy the bifocal ones, I mean the ones without the cuts on the middle of the glass. They are nicer but don't work as well as the other ones, not by a long shot.