Kowa's premium series of 82mm spotting scopes offer the ultimate in nature-viewing enjoyment.  These scopes are accompanied by several interchangeable eyepieces for your specific needs.  As a starting point, every user should have a zoom eyepiece, simply for its incredible versatility.  But eventually you'll want more, and that is why there are also fixed-magnification units available-smaller and sharper than zooms and a great compliment to your repertoire.

Choose an eyepiece with a wide apparent field of view(greater than 60°) if you don't wear thick glasses and want to be "swimming in field".  This will provide you with more real field for a given magnification than can ever be had from a zoom eyepiece, allowing easier subject tracking with the benefit of more observable detail thanks to the increase in magnification.

If you have to wear thick glasses, select an eyepiece with long eye relief.  These have a profoundly-long distance between the rear element and the location which your pupil can be while still being able to observe the entire field of view.   Naturally, this comes at the cost of less apparent field of view, but if you must wear glasses or sunglasses it is the most comfortable option for use.

Bayonet mounts

Eyepieces can be silently changed in the field

Brilliant helicoid-type twisting eyecup