Binocular Review
There are several things to remember when you are getting ready to purchase a pair of binoculars.
The numbers that are written after the binoculars name are very important. The first number is the amount of magnification the binocular has. The second number is the size of the optical lens. A binocular with the numbers 8X40 has a magnification of eight times and a lens size of 40mm. Although you can see objects that are farther away, binocular that have a magnification greater then ten start to loose image quality.
Binoculars that have lens that have a dark coating tend to withstand ..
Source: Binoculars