yes, scallops have eyes! Scallops have a large number (10?100) of small (about 1mm) eyes arranged along the edge of their mantle. These eyes represent a particular innovation among molluscs, relying on a concave, parabolic mirror of guanine crystals to focus and retro-reflect light instead of a lens as found in many other eye types. Additionally, their eyes possess a double-layered retina, the outer retina responding most strongly to light and the inner to abrupt darkness. While these eyes are unable to resolve shapes with high fidelity, the combined sensitivity of both retinas to light entering the eye and light retro-reflected from the mirror grants scallops exceptional contrast definition as well as the ability to detect changing patterns of light and motion. Scallops primarily rely on their eyes as an 'early-warning' threat detection system, scanning around them for movement and shadows which could potentially indicate predators.