IT is a known fact that if you are spending alot of time using a bino that you need, not want, a better lens system like the roof prism etc. Your eyes will fatigue faster with a cheaper bino. Cheaper bino's are alot tougher on your eyes for extended amounts of time. My opinion would be to get the best pair that you can afford. When it comes to optics you get what you pay for. JMHO.