Ancient

One of the earliest to study vision. Proposed that light comes from visible objects and travels to the eye.

Pythagoras 480 BC

Suggested that the eyes emits light. Vision occurs when light from the eye interacts with objects

Empedocles 450 BC

Supported Emission Theory (Active Vision). Believed rays come from the eyes and “touch” objects allowing us to see

Plato 428-328 BC

Opposed emission theory by proposing the Intromission Theory. Light comes from objects and enters the eye. Introduced the role of medium in vision

Aristotle 384-322 BC

Studied geometrical optics. Light travels in straight lines . Described the Law of Reflection

Euclid 300 BC

Conducted early scientific measurements of light

Ptolemy 160 AD

Proposed that vision involved pneuma (life force). Pneuma travels from brain → optic nerve → eye.

Galen 200 AD

Studied burning mirrors and lenses. Explained how curved mirrors and lenses focus light

Ala Ibn Sahl 984 CE