I think this is why one of the older analog video formats, I can't remember if it was VHS or NTSC, used less bandwidth for blue color than for the other colors. This was not noticeable unless blue letters were recorded, which always looked more blurry than letters in other colors.
Why we're blind to the color blue
101–110 of 218 posts
Re: Why we're blind to the color blue
#102Earlier quoted context omitted.
I’ve never met anyone without some astigmatism; especially, people with other vision impairment. Astigmatism is the number one cause of night blindness which is what you described.
You're precious. Why don't you tell me what else my eye doctor has never diagnosed me with?
9 in 10 people have some affliction of astigmatism. Astigmatism is just that your eye isn’t perfectly spherical. What does your eye prescription say in the cyl and axis fields, that’s your astigmatism correction.
Re: Why we're blind to the color blue
#103Earlier quoted context omitted.
I’ve never met anyone without some astigmatism; especially, people with other vision impairment. Astigmatism is the number one cause of night blindness which is what you described.
HN is so funny. 'I have no astigmatism.' -- 'Sure you do!'
Because nearly every person has some amount of astigmatism.
Re: Why we're blind to the color blue
#104Earlier quoted context omitted.
I’ve never met anyone without some astigmatism; especially, people with other vision impairment. Astigmatism is the number one cause of night blindness which is what you described.
pro tip: don't tell other people about their own experiences unless they ask you, and you're a professional.
Pro tip: nope
Re: Why we're blind to the color blue
#105I don't believe the blurred images at the end have anything to do with eye focus, as the author suggests. After all, chromatic aberration is blurring of only a very, very small amount. The demonstrated seemingly negligible perceptual effect of blurring blue to a huge degree in a multicolor image doesn't seem to have anything to do with that, but rather the fact that we perceive primary blue as a much darker color tha…
I'm not sure you're right. At night both I and my wife have reported difficulty reading glowing blue signs compared to glowing red/green signs at the same font size, brightness, and distance. I'm also not sure that the author is correct; the wrong-focal-distance explanation seems rather weak simply because our focal length is adjustable.
I have the exact same thing. It always makes me wonder why companies choose to have blue neon lights on their buildings because it's nearly impossible to read them when it's a thin font.
Re: Why we're blind to the color blue
#106Earlier quoted context omitted.
You're precious. Why don't you tell me what else my eye doctor has never diagnosed me with?
9 in 10 people have some affliction of astigmatism. Astigmatism is just that your eye isn’t perfectly spherical. What does your eye prescription say in the cyl and axis fields, that’s your astigmatism correction.
'eye prescription'?
Bruh. Read the comment of mine you replied to. 20/10 and 20/13 vision. I don't need prescriptions.
Re: Why we're blind to the color blue
#107Earlier quoted context omitted.
> In Europe and Asia, astigmatism affects between 30 and 60% of adults. https://en.wikipedia.org/wiki/Astigmatism
I can’t actually verify that number presented in that paper. I’ve looked and that stat is attributed to that paper, but there’s no evidence that the paper said that. Plus the paper is pay walled so unverified.
Considering the obvious inability for anyone to reliably know the astigmatism status of everyone they meet, not only is your anecdata unverifiable it's completely absurd.
Re: Why we're blind to the color blue
#108Could this be a factor in why we didn’t evolve to see a wider range of wavelengths? Is the visual spectrum just barely within the range that our brains can correct for the diverging focal lengths without needing additional lenses or modifications to the eye?
Water is relatively opaque at wavelengths above and below the visible spectrum. Air is also much more absorptive outside of the visible range. These two effects compliment eachother - water has a very sharp increase in opacity in the ultraviolet, while air has a sharp increase in the infrared. Our eyes are full of water and we look at things through air. Coincidentally, the visible spectrum matches the peak output from the sun. While you can go a little further into the infrared and ultraviolet ranges, there simply isn't much more to see, it would be as if we were looking through muddy water and dimly lit fog. Any mutation allowing you to see these wavelengths would convey no advantage.
Re: Why we're blind to the color blue
#109I would guess the deeper reason is that the sky is blue. That makes it more useful to have good vision in red and green. If we needed good resolution everywhere, we might have had eyes optimizing for different colors, four eyes, etc. Also, it isn’t as simple as this article describes. The human eye can vary its focal distance ( https://en.wikipedia.org/wiki/Accommodation_(eye) ) over a larger range than the effect of…
One theory I've heard is that hunting for fruit was probably a major driving factor in human color vision, as well as that of other primates. Good red/green vision would've helped our ancestors search for ripe fruit (usually red) by being able to easily distinguish it from foliage and unripe fruit (usually green).
Re: Why we're blind to the color blue
#110Earlier quoted context omitted.
See the very low coefficients for the blue channel when converting (gamma-compressed) RGB to luma. E.g. the common Rec. 709 standard assigns only 0.0722 weight to blue. Y' = 0.2126R' + 0.7152G' + 0.0722B'
Indeed, green contributes more. Example of the Y channel after blurring r/g/b: https://imgur.com/a/3p15Qe1 And colured versions: https://imgur.com/a/Knq2Ue3 (image source: https://en.wikipedia.org/wiki/Flower#/media/File:Flower_post... )
More, as in 10 times more for green, and 3 times more for red. So it's true that we're pretty blind to blue, just the "focusing" explanation is not correct...