...proves our proposition, because if the luminous body is a, the first, middle ray a o goes straight to the pupil of the eye; the lower one a m strikes on the convexity of the eyelids upon several of those lashes, and makes several images, which, once created, at once refract at the rim n that forms the thickness of the eyelid, and from here leap back into the light of the eye with all the images created in the lashes of the eyelids, which are somewhat long in shape and are separate and go with their points upward, spreading toward the ends, as the black eyelashes do. Now, to conclude our intent, I say: t s, between the origin of the light and your eye, you will cut the ray a m, whereby this ray will not be impressed on the convexities or curvatures of the eyelids, and for this reason the upper ray at n will fail, and consequently in the light of the eye, because, the cause of the images m being wanting, the effects of the rays at n will be wanting. Here then is defined why, by blocking the ray below the light, the ray above is entirely lost.

Here the adversary says that it seems to him such an image comes from the luminous body and passes between the eyelashes and is impressed in the thickness that the rims of the eyelids have, and that from there they leap to the pupil, and that this image is turned into rays because divided by the lashes through which it passed. Here it is answered that whoever should in such a case block the image below would not thereby lose the rays above, but