3 ms·

Would be interesting to know if dragonflies get red eyes when you take a picture of them with flash. Human eyes reflect some of the red light from the white fla

• seszett 2y ago
  I guess you're being downvoted because people think this is obvious, but dragonflies won't get red eyes because they don't have red blood to reflect the light. Red eyes are also caused by a particularity of vertebrate eyes, which have their blood supply in front of the retina. This is also the reason why you can sometimes see moving dots when looking at a bright, blue-coloured thing like the sky: your eye sees the whole capillaries filled with red blood cells, but the brain processes them out because they're always there. The large white blood cells then appear as "less red" dots in the processed-out streams of red, and the brain interprets them as bright dots. Insects have none of this, they don't have blood or blood vessels but a transparent haemolymph that doesn't really circulate through a complete circulatory system like us. So there really is nothing in front of the insects' light sensors to reflect light.
• wingspar 2y ago
  Went camping recently, and used one of those head mounted flashlights. Walking around there were glowing spots in the grasses. Thought at first it was some sort of firefly. Upon inspection, it was the light reflecting off the eyes of spiders. Dozens and dozens of spiders everywhere in the grasses. Never could get a picture. So light does reflect from compound eyes, but in ‘silver’.