Field-of-view activity: how far round can you see?
Pupils measure how far round they can see with a paper protractor and a partner, then compare their result with a horse (350 degrees) and a pigeon (316 degrees). People see about 200 degrees. Seated, 30 minutes, ages 8 to 14.
You need
- The printed protractor (page 2), taped flat to a table
- A pencil with a bright cap, held by a partner
- The data sheet (page 3) and a ruler
Steps
- Sit at the table with your nose over the dot and look along the "Straight ahead" line. Keep your head and eyes still: stare at a mark on the wall in front.
- Your partner stands behind you and holds the pencil at arm's length from your head, level with your eyes, over the 180 mark.
- The partner moves the pencil slowly forward round the right side. Say "now" the moment you first notice it. The partner reads the angle on the protractor below the pencil.
- Repeat on the left side. Do each side three times and use the middle value.
- Add left and right: that is your total view. Draw your bar on the chart and compare it with the animals.
Safety: the pencil stays at arm's length from the face at all times and moves slowly. Nobody stands up or turns round while measuring.
How your class compares
Every animal below has a measured total view from published studies. The dashed bar is for the pupil's own result.
Animals with eyes on the sides of the head see further round; eyes that face forward, like ours, see less of the world but share a wide zone that both eyes see, which helps judge distance. Try the field-of-view game to see each view from above.
Page 2: the protractor
Page 3: data sheet
Name: ______________________
| Try | Right side (degrees) | Left side (degrees) |
|---|---|---|
| Try 1 | ||
| Try 2 | ||
| Try 3 | ||
| Middle value |
My total view (right + left): ________ degrees
Which animal sees closest to me? ______________________ Which sees furthest round? ______________________
Why might an animal that is hunted need to see further round than one that hunts? ____________________________________________
What field of view should pupils expect?
Published measurements put people at about 200 degrees in total. Pupils' results vary with how still they keep their eyes and how quickly they call out, which is a good talking point about fair testing.
Why do horses and pigeons see further round?
Their eyes sit on the sides of the head. A horse sees about 350 degrees and a pigeon about 316 degrees, so only a thin slice behind them is hidden.
More to try
The science behind it: the measured angles and their studies