Why cant we look up at the sky for long without having to blink lots?

Answer 1

Because more dust reaches your eye than when you like straight ahead.

Blinking is like windscreen-wiping in cars...

Answer 2

because it's bright and it's an instinctive protective mechanism... it may not seem super bright when you're outside but that's because your iris and brain have already adapted to the ambient light levels. get a fixed aperture / exposure / ISO sensitivity camera & film (many digitals can also do this, in manual mode) and compare shots between your kitchen on a sunny day, a shaded outdoor passageway, and an open landscape (or your garden). If you standardise the settings to make the passageway look "normal" then the kitchen will seem very dark and the garden very bright, even though your concious mind doesn't pick up on it because of the automatic adaptions (which the camera would also do had you not locked it down). The external, automatic apparatus of your eye CAN pick up on this extreme condition though and applies some protective measures. This is also why only a nutter can stare at the sun outright without their body overriding the idea and forcing them to squint, shut their eyes, turn away etc - else they would be blinded. The sky isn't anywhere near so bad but its still "painful" to the eye on a bright day.

Answer 3

We blink to protect our eyes from dust, pollen etc. If you're looking at the sky and it's bright, your pupils (small black part of your eyes) get smaller, to reduce the amount of light coming in, sometimes we need to blink to help our brain re-focus on the light.

Answer 4

I can't look at anyhting for a long time without having to blink lots.

Answer 5

i can look at the sky for a long time but cant look at the sun for a long time

Answer 6

Please be careful if you are staring at the sun because there is no SPF for your eyeballs.