The text discusses the fundamental elements of eye anatomy and their depiction in artistic sketches. It explains how light rays interact with the optic nerves and the brain's inner surfaces, similar to how light behaves in a camera obscura. The text notes the significance of these concepts for the accurate representation of human figures in artworks.
The Human Representations, &c.
The fundamental basis of the eyes is broadly laid out, as was shown in the second proposal of this Lecture-Sketch. This Lecture-Sketch generally demonstrates the artistic trait of the open areas of the brain, the eyes, the optic nerves, and the pineal gland, suggesting that there is no need for us to spend more time explaining it.
Instead, consider in the said Print-Illustration how the rays of the object G. 1. 2. 3. intersect at the point of the eyeball, mistakenly making the object fall into the eyes B. B.; and observe in what manner they at each Point 1. 2. 3. touch the very end of one of the small threads of the optic nerves C. C., which optic nerves, as we have said, cover the entire surface of the eye with their terminal fibers. Their origin is in the inner surface of the brain D. Now, it lights the object G. in such a way that it is formed in the ground of the eyes in the same manner as bodies illuminated from outside in a dark room through an opening of a small hole against a canvas or paper. This movement of light causes a movement similar to the optic nerve fibers that spread out in the eye, as, for example, at Point 1. of object A. in the eyes B. B., the whole thread of the optic nerve was moved into the brain, as at D. 1., and similarly happens at the other Points 2. 3. or as many as one would want to envision. Always addressing as much space or room of the fibers as the opening.
Translation Notes:
Vertoog-schets: A term used to describe a formal presentation or lecture sketch. Gesigt-Zenuwen refers to the optic nerves. Pijn-Appel Klier should be understood as 'pineal gland'.