Intromission theory states that rays are reflected off objects into the eyes.

• A. Rays are emitted from the eye toward objects
• B. Rays are reflected off objects into the eyes
• C. Vision is caused by light scattering
• D. Vision is an illusion

Answer: (B)

The main idea being tested is how vision is explained by early theories: in intromission theory, rays come from external objects and enter the eye. The statement describes light being reflected off surfaces into the eye, which matches that view—the eye detects rays that originate from objects in the environment. This contrasts with an opposite idea where the eye itself emits rays toward objects (extramission). It’s also not accurate to reduce vision to a vague notion of light simply scattering, or to call seeing an illusion. Seeing involves light from surroundings entering the eye and being processed by the brain to form perception.