Can Green color give Rest to Eyes?
In our eyes, the dioptric difference between the dispersion of red versus blue light is approximately 2D. 

Remembering that the human eye's peak spectral sensitivity lies at 550 nm (green), the human retina is deliberately placed such that it is in between the dispersion of white light, i.e., between red and blue. This optimizes the best level of focus specifically for its peak spectral sensitivity. The pupil and the nucleus of the lens also help to minimize chromatic aberration.

In short, the eye is constructed such that it is easiest to focus on green light, which is in the middle of the visible spectrum and has the strongest receptors.