I don't use them.

All I ask is a large, fair type, a strong daylight or gas-light, and one yard of focal distance, and my eyes are as good as ever.

But if YOUR eyes fail, I can tell you something encouraging.

There is now living in New York State an old gentleman who, perceiving his sight to fail, immediately took to exercising it on the finest print, and in this way fairly bullied Nature out of her foolish habit of taking liberties at five-and-forty, or thereabout.

And now this old gentleman performs the most extraordinary feats with his pen, showing that his eyes must be a pair of microscopes.