Psychology / Unit 4 Psych 0398 short lesson, about 20 seconds
The Cornea and Lens
Captions available
The idea
The cornea and lens focus incoming light onto the retina, with the lens changing shape to focus at different distances.
In practice
The lens thickens to focus on a page held close and flattens to focus across a room.
Where people slip
Focusing is not detection. A perfectly focused image on a damaged retina produces nothing.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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