Why do you see the red/green/blue lines when you move your eyes back and forth while looking at a video from a projector?
Those different color lines make the picture. When you look without moving your head, the lines blend together to make all the different colors. These lines are projected one after another.
The Short Answer
Those different color lines make the picture. When you look without moving your head, the lines blend together to make all the different colors. These lines are projected one after another. The eyes have this thing called "persistence of vision." That is, if they see a bit of light, the eyes seem to keep seeing it for a short time; that's how the eye blends the projected colors together. A projected picture changes the image more rapidly than the eye can follow the individual changes, so you don't see individual bits of image, but a moving image. If you look at an image made up of individual bursts of color, that depends on you just looking at it, and instead move your head or eyes side to side, then your eyes don't see the different lines on top of one another, blending together, but next or near to one another… suddenly you see the parts that make up the image.
Analysis
Key Concepts: Image, lines, eyes
This explanation focuses on image, lines, eyes and spans 160 words across 7 sentences. At 132% above the average Human Body explanation (69 words), this is one of the more thorough answers in this category, reflecting the complexity of the underlying question.
What This Answer Covers
The explanation opens with: “Those different color lines make the picture.” It then elaborates by presenting a contrasting perspective, ultimately building toward a complete picture across 7 connected points.
How This Compares in Human Body
Ranked #15 of 500 Human Body questions by answer depth (top 4%). This places it in the comprehensive tier — the top quarter of most thoroughly answered questions. Questions at this depth typically involve multi-faceted topics requiring nuanced explanation.
Frequently Asked Questions
Is there a simple explanation for why you see the red/green/blue lines when you move your eyes back and forth while looking at a video from a projector?
Those different color lines make the picture. When you look without moving your head, the lines blend together to make all the different colors. These lines are projected one after another. The eyes have this thing called "persistence of vision."…
How detailed is this explanation compared to similar Human Body questions?
This is one of the most thorough answer at 160 words, ranked #15 of 500 Human Body questions by depth. The key concepts covered are image, lines, eyes.
What approach does this answer take to explain you see the red/green/blue lines when you move your eyes bac?
The explanation uses contrasting perspectives across 160 words. It is categorized under Human Body and addresses the question through 1 analytical lens.