Field notes / plate 003 / raptor vision
Haliaeetus leucocephalus
One eye, two artistic studies. Examine its folded pecten, meet two foveae, and slide a third eyelid across the cornea.
Choose a part • opens an enlarged inspection view
Folded, vascular tissue rooted near the optic disc and projecting into the vitreous. It supports retinal metabolism; recent work in birds highlights glucose supply and lactate removal rather than a simple oxygen-delivery story.
01 / A different retinal view
Bald eagles have central and temporal foveae. Explore their different viewing directions without forcing both into one section plane.
The central fovea projects into the lateral visual field.
Right-retinal map and top-of-head direction inset are separate schematics. Nasal is left and temporal right on the retinal map. The head points its beak up. The temporal projection is near binocular overlap when the eyes are converged; no measured angle, spacing or visual performance is encoded.
02 / Outside the cutaway
The nictitating membrane moves across the front of the eye from the nasal side. This external lateral view keeps it separate from the internal cutaway.
Retracted
Movement is a slow, controllable illustration, not a measured blink. In both art styles, the sheet and edge follow the same state.
A folded support structure
It rises from the optic-disc region into the vitreous. Its folds hold a rich vascular surface. Research in birds links the pecten to retinal metabolic support; a 2026 study emphasizes glucose delivery and lactate removal. Those experimental measurements are not presented here as bald-eagle-specific values.
A reinforced anterior wall
Scleral ossicles form an anterior ring near the corneal margin. The drawing exposes a few cut edges to identify the structure; their number and exact arrangement are not a bald-eagle specimen count.
A common optical plan
From outside inward: sclera, choroid, retina, then vitreous. The pupil is an iris opening, with the lens behind it. Aqueous lies in front of the iris. The vitreous cavity is behind the lens.
The paired cutaways are AI-generated anatomical illustrations, guided by an original code geometry and individually inspected. The colour study aims for hyper-realistic material and lighting; it is an illustration, not a biological photograph. The ink study interprets the same anatomy through varied contours and hatching. Fine texture is artistic, not resolved histology.
Not to scale. Cut-wall thickness, pecten detail and anterior ring exposure are exaggerated for learning. The viewing plane is simplified; the two foveae and membrane are deliberately separate. No clinical, veterinary, acuity, ultraviolet or prey-distance measurement is provided.
Made using Anatomy by Ryan (wheresryan22): SVG composition, figure/page frames and interaction guidance. Our drawings and adaptations imply no creator endorsement or scientific validation. About this collection and the upstream MIT licence.