首楞嚴義疏注經 4.453

4.453

"Ānanda! You should furthermore determine their superiority and inferiority among them. As when the eye observes and sees: behind is dark and before is bright; the front direction is completely bright, while the rear direction is completely dark; looking to the left and right sides yields two-thirds. Synthesizing all that it performs, its virtues are incomplete: three parts express the function, while one part lacks the virtue. You should know that the eye has only eight hundred virtues."