lover,These affordable yet feature-packed binoculars are designed specifically for beginning to intermediate users

What is the difference between 8x42 & 10x42
In a binocular power rating (e.g. 10x42) the first number is magnification. 10 times larger than normal unaided vision;the second number is the diameter

of the objective lens,the objective lens diameter determines light  gathering capability and the size of the field of view. a higher magnification is

not necessarily a good thing, as it is more difficult to maintain a stationary image, the light gathering capability is often  impaired,

and the field of view is reduced. for most uses, a binocular of 7 or 8 power is about right.

10 power is good for people with steady hands, and 12 power often requires a tripod to hold a stable image

Do these work with eye glasses or do I need to remove my glasses to look through them
eyecups are adjustable; works fine with glasses

How far can you see with these (i.e. 5 miles/10 miles)
Basically, if you can see it with the naked eye, these will amplify what you see 8 times. It will also capture more light so you can see things better at a distance

the other spec they give you is field of vision, which means that at the distance stated, you will be able to see things within that range. In this case, Field of View is 341ft/1000 yds;114m/1000m

Binoculars don't really state a specific distance. If you can see it, the binoculares will help you see it better. that's the rule

How good are for bird watching
Very good. that's why I got them and it does a very good job. you can see them very clearly