Light blue eyes here.

The OP is accurately describing a perfectly normal variation on the human biology, adapted to northern, cloudy, forested parts of the world.

I sneeze whenever I go out into bright sunlight.

Although I have found very little written about this, by asking other people about it, I have found that some very light-eyed people also have this reaction.

Apparently it is hereditary.

Anybody else with light eyes sneeze when stepping into sunlight?