TED-Ed: What are those colors you see when you rub your eyes? | Paul CJ Taylor

The video explores Newton's experiments with eye safety, focusing on afterimages and visual illusions. It explains how photoreceptors in the retina process light to create images and discusses theories behind positive and negative afterimages. The video also covers pressure phosphines, visual effects caused by physical pressure on the eyes, and other phenomena like cosmic radiation-induced illusions.

What was one of the unsafe experiments conducted by Newton to understand visual phenomena?

• He looked directly at the sun.

• He stared at a bright light bulb.

• He used a magnifying glass on his eye.

• He wore colored glasses.

What is the role of photoreceptors in the eye?

• They control eye movement.

• They convert light into signals for the brain.

• They produce tears.

• They detect sound waves.

What happens to photopigments during the bleaching process?

• They stop functioning completely.

• They become more sensitive to light.

• They temporarily alter their molecular structure.

• They change color permanently.

What is a positive afterimage?

• An image that appears only in black and white.

• An image that appears in complementary colors.

• An image that appears in the same colors as the original.

• An image that appears darker than the original.

Which cells are thought to be involved in the creation of negative afterimages?

• Retinal ganglion cells

• Optic nerve cells

• Corneal cells

• Lens cells

What are pressure phosphines?

• Visual illusions caused by light exposure.

• Visual illusions caused by physical pressure on the eyes.

• Visual illusions caused by sound waves.

• Visual illusions caused by temperature changes.

What phenomenon do astronauts report when exposed to cosmic radiation?

• Hearing strange sounds

• Feeling weightless

• Seeing flashes of light

• Experiencing dizziness