Scallop
Reference: Scallop
The honest answer to “what actually has eyes all over it.” Up to 200 working eyes in a row along the mantle edge — and they focus with a mirror, the way a reflecting telescope does, not with a lens.
Scored on every axis
A row of telescopes in a shellfish
Open a live scallop and the gap between the valves is lined with small bright eyes staring out. Each one has a retina, and behind the retina a concave mirror built from stacked guanine crystals which throws the image forward onto the retina from behind. It is a reflecting optical system in an animal with no brain to speak of — imaged in detail and published in Science in 2017.
Neighbours on the same axis: the chiton (Acanthopleura granulata) grows up to a thousand eyes with aragonite lenses set into its shell plates — the armour is the eye; the starfish carries an eye at the tip of every arm; and the box jellyfish has 24 eyes in four clusters, some with real lenses, and still no brain.
Which is why the peacock comparison is backwards
Put the two side by side. The peacock has about two hundred eyes that look like eyes and cannot see. The scallop has about two hundred eyes that do not look like much and see. Display and function came out at the same number by completely different routes.
The invertebrate line does this repeatedly: distributed vision with no central image, no face, and no head to put a face on. Every vertebrate instead got two eyes on a head, and none has ever got more — the same kind of inherited ceiling as the four-limb constraint, and one reason the throne-room beings of Ezekiel and Revelation read as impossible in vertebrate terms while being perfectly ordinary in molluscan ones.