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Section II: How We See the World
How we see the world
- How do our eyes (and brain) determine where something is in space?
- How do we determine how far away it is?
- How does our brain determine how much the eyes need to focus?
The answer . . .
- The brain relies on certain basic visual clues
- Depth perception is provided by our two eyes
- We perceive contrast between objects
- Color change between objects helps our brain
- Well-defined edges of objects also help
With near objects
Contrast helps
- Example: black print on white page
Good edge definition also helps
- immediate change from the characters to the background
What happens . . .
- when our eyes don’t find good contrast or well-defined edges?
- A good example is when we are driving in a whiteout or fog
Accommodation or Focusing
- There is less accurate focusing
- Ciliary body muscles must work harder
- This creates fatigue over a period of time
Try this exercise
- Look out a window and let your eyes completely relax
- Turn and look at your finger with it about 12 inches away
- Notice how your eyes have to focus closer and converge in able to see your finger clearly
To continue, click on Section Three, Lesson One in the left column
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