What are visual percepts called that originate from the eye itself instead of an external object?

The term for visual percepts that originate from within the eye, rather than from an external object, is known as entoptic phenomena. These experiences are the result of visual sensations that arise from structures within the eye itself, such as the retina or the vitreous humor, and include occurrences like seeing floaters or flashes of light.

For example, floaters are tiny spots or threads that drift through your field of vision, caused by small clumps of gel or cells inside the vitreous, which is the gel-like substance that fills the eye. These visual experiences are distinct from external perceptions because they do not require light to enter the eye from the outside world; instead, they are inherently linked to the eye's internal state.

Other terms provided in the options, such as visual synapse, retinal reflection, and perceptual illusion, refer to different concepts. Visual synapse is more related to the connections between neurons in the visual processing system, retinal reflection can imply the reflection of light from the retina which does not pertain to self-generated visual experiences, and perceptual illusion involves misinterpretations of external stimuli rather than internal visual phenomena. Thus, entoptic phenomena are specifically defined by their origin within the eye itself.