Helicopter pilots have GOOOD EYES..............

[MerryDown]

Have a go people.......................anyone able to explain why?


http://www.patmedia.net/marklevinson/cool/cool_illusion.html

[tall and tasty]

Possibly to do with your rods and cones in the retina but not sure.

But is you look to the side you actually see green and pink dots going around even stranger

This may explain it for you

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html

or google rods and cones of the eye and numerous good sites come up

TnT

[Whirlygig]

Yup.

The rods do light and dark, the cones do colour. Cones are concentrated around the fovea at the back of the retina whereas the rods are over the rest of the retina. So when you stare at a black cross, the image of which is being centred on the fovea (where the cones are), the rods, which pick up the rotating circles, can't distinuguish the colour. Not sure why one remains though and why it is the complementary colour - haven't got to that chapter yet!!

This is why if light levels are low, you should look slightly away from the object which you actually want to see because the rods are not plentiful at the fovea.

Or something like that!

Cheers

Whirls

[SASless]

Whirls,

I am beginning to worry about you.;)

[Whirlygig]

Aw Sassy, that's awfully sweet! But why worry? Surely Human Factors and Pilot Performance forms part of your bed-time reading too!

Cheers

Whirls

[Thomas coupling]

Doesn't happen to color blind persons. They cant see the change to green.....

[PhilJ]

More optical illusions and explanations than you could ever want here:

http://www.michaelbach.de/ot/

scroll down to colour and lilac chaser

[Farmer 1]

I understand about the dots, but where do the elephants come in?

[Bertie Thruster]

How do you tell an elephant from a grape?

[Farmer 1]

Talking of elephants, how do you get down from one?

[cyclicmicky]

How do you know if an elephant has been in your fridge?


Footprints in the butter:}

How do you know if two elephants have been in your fridge?

Two sets of footprints in the butter:D

How do you get four elephants in a mini?

two in the front two in the back:O

How do you know if four elephants have been in your fridge?

Theres a mini parked outside:E :8

[Farmer 1]

How do you get four elephants in a mini? You use a potfer, stupid!

[Devil 49]

Great stuff, and I'm going to spend some time exploring this.

A number of years ago, I saw one of these that demonstrated the blind spot and the brain's effort to compensate. It was a plaid field with a gray area. When your gaze was directed at a certain point, your blind spot covered the grey, and the brain's visual processing filled it in with the surrounding plaid pattern. Anybody else seen it, can you name it? Or better yet, provide a link?

[Bertie Thruster]

Ah, grey areas!

Elephants are grey

Grapes are mostly green.


So how do you tell the difference if you are colourblind?

[Simon853]

I read somewhere years ago that the sensitivity of the rods is almost into the near infra-red, and that "they" believe some peoples vision might extend into it. Of course you wouldn't actually see the white-hot kind of enhanced nightvision picture we're familiar with, you simply get an impression there was something there in the dark.

Anyone know if this is true?

Si

[petitfromage]

Whirlygig is absolutely correct! Well done.
Its known as the Troxler Effect.

Fovea? Thats an awfully dirty word.

[Whirlygig]

I'm sorry, I didn't realise I was talking dirty but I'll continue if you want.

Cheers

Whirly (fovea) gig

[[email protected]]

No petitfromage... crevice is a dirty word.