A pink, internal odontophore and buccal mass can be seen through the translucent, white head.
The tapered, translucent white cephalic tentacles each have a black eye with a tiny opening on the dorsum of the slightly swollen tentacle-base . The opening is at the apex (1) of an internal cone of black pigment that, because visible through the translucent flesh, gives the false impression of a larger opening. Some or all of the black may be pigmented retinal cells. The eye can probably differentiate light from shade, and detect the direction of the light source, but cannot discern shapes.

Concise
Part 1, SHELL FORMS: 02 Patella pellucida. Growth Stage 2 (GS2). July 2012. Littoral. North Yorkshire, England. © P. Lightfoot.
Part 2, BODY & ANATOMY: 03 Patella pellucida. Growth Stage 3 (GS3). 2009. Sublittoral, Farne Islands, Northumberland, England. © P.Lightfoot.
Part, 3 HABITS & ECOLOGY: 04 Patella pellucida. Length 4.6mm. Growth Stage 3 (GS3). September 2016. Yorkshire, England. © P.Lightfoot.