I was sure that I’ve read by moonlight in the past, and to check I wasn’t misremembering I just went out into the back garden, away from any artificial light source, and read a page of a book by the light of the moon. It’s not hard - granted I wouldn’t want to try and read a whole book by moonlight, but it’s very doable, and the sky is even a little bit misty. So, am I one of the people who “have extra-sensitive cones or an extra helping of rods that do allow them to read in the brightest moonlight” mentioned in that link? I know my eyesight is far from exceptional - I have amblyopia and consequently no stereo vision, for one thing.
Poll to follow: the moon is only a day or so off full at the moment, so if you can, and if it’s dark where you are and you can see the moon, go outside and try it.
I just grabbed a flyer and went outside to read it I could see it pretty clearly, but smaller print would be a strain. The lights of the town glow over the hill, but there’s little artificial light where I live. Also there’s some sort of hazy thing going on so the moon could be brighter, and will be once it gets overhead. It’s bright enough to see blue and yellow, but the red just looks dark.
My night vision is not bad, I know from standing night watches on boats.
I said no based on memory. You certainly can’t read a map. But if the print is large enough, it should be possible. Also, allowing time for your eyes to adjust to the low light level should help.
I have heard and have demonstrated to myself to be plausible the following: after 30 minutes of darkness adaptation, an average human’s eyesight is more acute than that of a rabbit and almost as acute as that of an owl.
If you go outside right now here in East Tennessee, you will see an almost full moon shrouded with clouds. If you try to read something by that light, well, the font had better be pretty large.
But, if you sit down and watch the stars as the planet revolves and watch the rise of certain stars for the better part of an hour, you will notice that the trees around you appear to be glowing brighter. No, those mushrooms you ate earlier were just Portabellas.
What you are experiencing is the expression of a chemical known as Rhodopsin or more popularly ‘visual purple’ that is secreted by cells in the retina. As far as I understand (and I am not an eye doctor), this chemical allows for the rods to absorb and process light more effectively. It is almost instantly photobleached by light and its regeneration takes about 30 minutes in most humans. But, when it is active, is allows very small amounts of light to be triggered by your rods so that a black and white image is constructed in your visual cortex.
So, after all of this cool stuff happens (even without you knowing it) you may find that the total lumens available from a full moon on a clear night might allow you to read a book, assuming that the pages are bleached white and the text is true black.
I can’t imagine that such experiments have not yet been conducted.
Wouldn’t light pollution actually help rather than hinder? Sure it will hinder you from seeing stars in the sky, but it will mean more light reaching the ground.
Edit: and Gagundathar, when I tried this earlier tonight, I just went outside into the back garden, away from any light sources, and let my eyes adjust for a minute or two. No long adaptation required.
Again, I struggle to see the logic here. Surely any extra light pollution would be an advantage, not a disadvantage, if you’re trying to read a book rather than stargaze?
Not sure what that looks like. I remember trying to read a road atlas one time. Only the highway lines were clearly discernable, none of the print. As I said, the size of the print and time to adjust to the low light level were important. I was probably ruining my night vision by repeatedly trying to see better with a bic lighter.
Also, over desert areas the moon seems much brighter. I don’t know if it actually is brighter though, maybe the air is less humid and there’s less scatter. I don’t think scattered light helps, it would tend to make edges less well defined.
Dunno. It could be that being out in remote areas and not around bright electric lighting your eye tends to be more readily adapted to night vision. Plus, light pollution tends to go along with air-pollution so maybe you’re getting a bit more light hitting the page & reflecting back?
I just tried it and was able to read a piece of paper with “standard” size lettering on it, away from any streetlights and clear skies (which can reflect light). I have also always been able to easily see my shadow when the Moon is full; in fact, I can even make it out a bit when standing across the street from a streetlight.
I just tried reading at 3:30 a.m. under the Neil Armstrong blue moon in a clear sky, with the moon looking over my back and shining driectly on the page that I was reading. I could not read without the moonlight shining directly on the page.
While wearing my usual reading glasses, I was able to read 8 point with difficulty, 10 point without difficulty, and 12 point with ease.
While reading the same sheet inside under bright light a few minutes later, I was able to read 8 point without difficulty, and 10 point with ease.
Conclusion: it was easier to read under a bright light than it was under a bright moon, but yes, I could read normal sized text under the bright moon.
This confirms my memories of having read under the moonlight in the past, which is how I answered the poll.
I just got around to trying this last night, three days after the full moon, and I couldn’t read regular text in a book. We had a fire going, but I looked away and closed my eyes to let them adjust to the dark for about five minutes, to where I couldn’t see a glowing patch in my center of vision any more.
I could read the cover, and the chapter titles. The section headings I could make out maybe half the words. But the regular text was unreadable, even though it looked like I should be able to read it. It wasn’t a “Large print” book, but the print was fairly big, larger than newspaper or paperback text.
Until a few years ago, I could. But since then, I’ve become farsighted, and had to start wearing reading glasses (usual middle-age stuff). I haven’t been able to read without light since then.
That’s one nice thing about a Kindle- it provides its own light, and I can read in the dark when I can’t sleep.
