It is on account of this that so many people wearing glasses are run over.
When in addition to this they cross a road holding an umbrella well before their glasses, it is best to stop the horse and wait till they are across.
This adjusting of a glass for a fixed distance can be seen with deer-stalking telescopes and Zeiss glasses.
When spying for a deer one makes a mark on the draw tube to suit one’s usual spying distance, which is about one thousand yards.
One can see deer clearly with this adjustment from the one thousand back to about three hundred yards, but for a closer view you have to readjust the focus.
If with the focus correct for the one thousand yards you attempt to look at an object only as far off as your back sight or even your front sight, you will see only an indistinct blur.
A near-sighted man, shooting a pistol full arm stretch, without his glasses, sees his back sight a blur and his front probably not at all, and the target like a post impressionist picture.
If he puts on glasses to see his hind sight properly, his front sight will not be distinct, and the target still more indistinct.
I think for a near-sighted man it is best to have glasses made so that he can see his front sight very clearly.
Then he would see the man target at twenty-five meters quite well enough to be able to hit it. It is not necessary for him to see his back sight distinctly.