What is 'optimal viewing'?

Answer 1

If you gave us more information, like in what context you heard the term, we might be able to give you a better answer.

In general it can mean "optimal viewing angle" or "optimal viewing distance".

Sometimes it helps to know how far away to sit from the TV (or knowing your couch is 9 ft from the TV - what size is optimal).

I have included a link to a seating distance calculator below.