I dont know whats in that book but their are many exercizes to help all your sences. Ninjas would stay in caves with no light some times for days before a big night operation. And after that kind aclamtion to the eyes and other sences, makes night time like day time even with little or no moon. For distance you focus and far and hold, near same thing. Start small (like 20 sec 3 times a day) and dont strain and always breath normal. Things to help vison dont hurt either(vitamins, diet, etc). However if you got eye desises or hereditar problems you need more like sugeries or what ever the doc can help with. Vison improvments are small if any but getting the eye aclimated to your vison is a big improvement all together.