The Foundation of Vision: Light
Published:
(work in progress…)
Human vision perception is highly adaptive and sophisticated. It is the suprior sense among all five human sensories. Human perception is a complex process that involves the light, scene, eyes, and brain working simultaneously to translate the reflected light into a vibrant spectrum of sensation. It is important to note that, not all sensory information collected by our brain is processed equally. More relevant information is selected while discarding the rest, while keeping a stable and coherent perception of our surroundings (Navarro et al.). The visual process starts from Almost half of the primary visual cortex is engaged in vision (Coltekin et al.) in which 25% is devoted to processing data from the central visual angle 2.5° (Johansson et al.).
Consequently, light is the key factor and plays the most crucial role in visual perception. From the Physics perspective, light can be described as the wave or photon. However, from the 3D rendering point of view, other than the domain specific wave optics (e.g., Wavefront Path Tracing), the light is described as photon. The word Photo orginated from the Greek word phos, meaning light.
If we look at the history of human’s understanding over the light and its interaction with the scene and finally reach human eye, there are three pre-dominant theory:
1. Emission (Extramission) Theory: Both Euclid and Ptolemy believed, the light emits from human eye.
2: Intromission Theory: Aristotle (De Sensu)
3. Modern Theory: The most modern theory of light perception is provided by Alhazen Ḥasan Ibn al-Haytham. From his empirical studies he summarized, vision occurs when light rays reflected from objects enter the eye, where they are focused by the lens onto the retina.
References
- Jiménez-Navarro, D., Serrano, A. & Malpica, S. Minimally disruptive auditory cues: their impact on visual performance in virtual reality. Vis Comput 41, 5059–5073 (2025). https://doi.org/10.1007/s00371-024-03707-6