Optical Illusions and How We Percieve Colour with Andrew Hansen #shorts #opticalillusion #science

Why It Matters

Grasping how after‑images and retinal fatigue shape color perception aids designers and clinicians in crafting visuals and diagnosing vision deficiencies, impacting both consumer experience and eye‑health research.

Key Takeaways

• Staring at a point creates complementary after‑image colors.
• Retinal cells fatigue, causing temporary blindness to original hue.
• Three cone types encode blue, green, and red wavelengths.
• After‑images reveal how color‑blind individuals perceive hues differently.
• Perception combines sensory input with brain’s expectations, creating illusory colors.

Summary

The video explores how humans perceive color through optical illusions and after‑images, using a simple experiment where viewers stare at an elephant image and then observe the complementary hue that appears when the picture is removed.

Andrew Hansen explains that prolonged focus fatigues specific retinal cells, rendering them temporarily blind to the original color and causing the brain to generate the opposite hue. He references Maxwell’s after‑image studies and notes that variations in cone response—blue‑sensitive, green‑sensitive, and red‑sensitive cells—produce the three‑dimensional experience of color, while color‑blind viewers see different after‑images.

He illustrates the concept with anecdotes, such as prompting the audience to “make an R noise” after blinking, and recounting a failed demonstration using the Belgian flag that highlighted how expectation shapes perception. Visual metaphors, like a “psychedelic bed sheet over furniture,” emphasize the brain’s role in filling gaps.

Understanding these mechanisms matters for designers, marketers, and vision scientists, as it reveals how expectations and retinal physiology combine to create vivid, sometimes illusory, color experiences, informing everything from advertising palettes to clinical assessments of visual disorders.

Original Description

Colour isn’t just what you see, but what your brain constructs. 👀Physicist Andrew Hanson tells us how a simple illusion helped James Clerk Maxwell uncover how we perceive colour.

Watch the full talk: youtube.com/watch?v=af78RPi6ayE