1
It is written: "Truly the eye of Ad-nai is on those who fear Him, who wait for His faithful care" (Ps. 33:18). And it is [also] written "the eyes of Ad-nai, ranging over the whole earth" (Zechariah 4:10). If they merit, the eye of Ad-nai is on those who fear Him. If they don't merit, the eyes of Ad-nai ranging over - the lower eye.
2
As it is taught: why did Yosef merit that the evil eye would not rule over him? Because he merited to consider the higher good eye, as it is written: Yosef is a son of favor, a son of favor above the eye (Gen. 49:22). Why is he a son of favor, above the eye? It is due to the reason of the eye that looks on him.
3
And it is written: a good eye is blessed (Prov. 22:9). Why? Because he gave from his bread to the poor.