It’s not the eye at all. The graphics where there is an eye and then waves and particles and slits and a wall or whatever, are misleading. The “eye” is some sort of particle or wave detector or something. It’s a measurement device. The human eye only comes in at the point of reading the output of that device.
Now you’re making me go and look this all up and find out if I know what I’m talking about or not. Good thing I’m retired. 