skywatcher
Snowy Owl
Joined: Sep 03, 2008
Posts: 126
Location: Ironton, OH
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 Posted: Sun Nov 02, 2008 6:11 pm Post subject: |
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Maybe if I lived in a apartment that actually invested in overhead lights my eyes wouldn't have burned out the past three months.
Anyway, my scores were:
Accuity dec. VA: 1.04, Snellen fraction: 13/13
Threshold contrast 0.9%
Which I'm guessing that my contrast ratio sucks and I can see things pretty far away to get a perfect score on that. I'm also borderline nearsighted, which is the most ironic thing of all. I don't doubt this at all, I have measured 20/15 vision, and probably would bust the crap out of the optometrist's charts were it not for the lighting there causing this eerie glare that I cannot penetrate (and need two eyes to do so unless I want glasses I don't need).
I had no idea what the heck that Vernier thing was. I worked around with it for the past ten minutes and gave up. Maybe they need something like instructions for us people who don't know what the heck a Vernier is other than a caliper.
Skywatcher
-I watch the sky... hopefully not running into things, though. |
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Dr_Wishful
Butterfly
Joined: Oct 26, 2008
Posts: 11
Location: California
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| Posted: Sun Nov 02, 2008 6:46 pm Post subject: |
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| skywatcher wrote: |
Anyway, my scores were:
Accuity dec. VA: 1.04, Snellen fraction: 13/13
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You probably didn't go into the preferences and set the calibration bar and the observer distance. You will likely need to be at least 2m from your monitor for this test to work properly. I have not run a valid test yet because I can't get that far from my laptop monitor. If you scroll down the page to the Details -> How to Calibrate section, you will see some additional information.
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I had no idea what the heck that Vernier thing was. I worked around with it for the past ten minutes and gave up. Maybe they need something like instructions for us people who don't know what the heck a Vernier is other than a caliper.
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Vernier doesn't have anything to do with the content of the blog article. I used the arrow keys to indicate whether the upper line was on the left or right side of the lower line. |
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Mosse
It'll all come down with me...
Joined: Sep 23, 2008
Posts: 1248
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| Posted: Sun Nov 02, 2008 7:04 pm Post subject: |
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The Vernier and the Acuity were pretty easy, until the Vernier lines were parallel. 
The Contrast one is impossible. |
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Electric_Kite
Phoenix
Joined: Aug 21, 2008
Age: 38
Posts: 588
Location: crashing to the ground
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| Posted: Sun Nov 02, 2008 7:07 pm Post subject: Re: Autistics Have Better Vision Than Birds of Prey |
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| Dr_Wishful wrote: | Has anybody perused the literature enough to know what are "normal" numbers and what are "birds of prey" numbers?
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Well, the Snellen fraction is the visual acuity quantifying format thing we're used to: 20/20 (or 6/6 in metric) is normal human visual acuity -- standing twenty feet away from the standard Snellen eye-chart, the person can read the '20' line. 20/40 means you must stand twenty feet away to read something that a normal person could read at forty feet away. The regular test that your eye-doctor probably uses maxes out at 20/10.
(I understand that actually, normal 'perfect' human vision is slightly better than 20/20, it's more like 20/16, but the standard test isn't that precise.)
Diurnal raptors test between 20/6 and 20/2. So a hawk could read fine print from twenty feet away, if it could read. I don't know how they tested this, though.
I am quite myopic, and when I got my last glasses my corrected vision tested at 20/10. The doctor let me choose between lenses that gave me 20/20 vision and the ones that made it 20/10. He said that it was rare to be able to correct somebody's vision to make it better than 20/20, and that most people who could get that got headaches from wearing glasses that did it. I went for 20/10 anyway (and now need new glasses to get it back, and hope that it's still possible.) When the eyeglasses were made and I went to pick them up from the optical shop, the man who made them had me test them by reading a street-sign down the block from the shop. I read that one, and the next street down, a little performance that startled him, as appearantly it significantly exceeded expectations for 20/10 acuity.
Probably the kinds of tests we can devise for raptors, and the comparison, are flawed.
The structure of a hawk's eye is somewhat different from your own. There's a patch on your retina, the fovea, where the cones are more densely clustered. It's round and right in the middle of your retina, which is why the stuff in the center of your field of vision is in sharp focus, but your 'peripheral vision' is blurry. A hawk's fovea is an arc across the top of its retina. Remember that the lens turns the image upside down. Everything in the bottom half of the hawk's field of vision is projected onto the fovea and is sharp, everything in the top half is blurry. Makes sense if you're a hawk, you are looking for prey on the ground and don't really need to see anything above you clearly, just know that it's there. Dogs and horses and cattle and a lot of other animals have a streak-shaped fovea in the middle, also sensible -- standing with its head held up normally on a relatively flat plain, the clearest part of the beastie's field of vision is the horizon. Probably a very different experience from our own.
Plus there's all this stuff in the brain that controls what you actually do see. Most familiar animals tend to pick out movement very well, but ignore shapes. They're mostly looking for predators or prey. Human beings pick out shapes well, which makes perfect sense when you're an animal that uses vision to forage for plant-foods, can eat only certain ones. Our ability to see the colour red (a rare thing in mammals) probably has everything to do with our inability to stomach unripe fruits.
I can't figure how to make an eye-test that would accomodate for the little physical differences and the larger difference in how the brain processes the input and 'decides' what to give cognitive attention to. You can't do it by microscopically examining an eye; the density of light-responsive cells on human retinas makes it physically possible for a person to get much better image resolution than people do. |
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HarryWilliams
Sea Gull
Joined: Apr 07, 2008
Age: 115
Posts: 226
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| Posted: Sun Nov 02, 2008 7:24 pm Post subject: |
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I think the snellen decimal of the best performing subject was about three, which is about 20:6.5, I think, with an average of about 2.8
The report says that falcons have a snellen decimal of around 2. |
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FrogGirl
Phoenix
Joined: Oct 14, 2008
Age: 38
Posts: 770
Location: Lost wherever I am
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| Posted: Sun Nov 02, 2008 7:29 pm Post subject: |
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| Without my glasses, I can't see clearly, any further than I can reach. Without my glasses, I can't legally drive. With my glasses, as long as they are the correct prescription, I can see very well. |
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KRIZDA88
Sea Gull
Joined: Feb 12, 2007
Age: 25
Posts: 236
Location: Peoria, IL
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| Posted: Sun Nov 02, 2008 7:50 pm Post subject: |
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Was cross-eye for the first part of my life and have had bi-focals in my glasses since the first grade. I wear contacts most of the time now. I'm nearsighted as well, but what i can see clearly without my glasses has always been pretty good, could even read micro-print for a long time, not sure how well I can do that now. Bad eyes are prevalent in my family especially on Dad's side. I have better vision than my youngest sister though her prescription has already surpassed my Dad's in strength and she's only 16.
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kurtsemler
Raven
Joined: Oct 30, 2008
Age: 29
Posts: 115
Location: Pullman WA USA
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| Posted: Sun Nov 02, 2008 8:30 pm Post subject: |
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My results:
dec. VA: 1.04, Snellen fraction: 13/13
Threshold contrast 0.89%
Vernier threshold: 0.28 arcmin |
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Aguila
Blue Jay
Joined: Sep 21, 2008
Age: 18
Posts: 99
Location: In a galaxy far far away...
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| Posted: Sun Nov 02, 2008 8:32 pm Post subject: |
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without my glasses I got
VA:2.0 Snellen Fraction 13/7
Threshold Contrast .38 %
Vernier threshold .01 arcmin
With one lense in my dominent eye--I am closing the other (one of my teachers steped on my glasses)
VA:2.0 Snellen Fraction 13/7
Threshold Contrast .36 %
Vernier threshold .00 arcmin
I did not mess with the preferances and I dont really understand the numbers. Does anybody understand these numbers? |
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outlier
Phoenix
Joined: Oct 17, 2008
Posts: 1526
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| Posted: Sun Nov 02, 2008 9:16 pm Post subject: |
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The study looks very interesting. Am curious to see it if/when they replicate it with more subjects.
Will not be able to try the tests for a couple of weeks: have been putting off visiting the optician to get new lenses... neglected to do so for 5 years (and been walking around in a blur), but this thread has encouraged me to endure another eye exam! |
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AgentCROCODILE
Snowy Owl
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Joined: Sep 17, 2008
Posts: 165
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| Posted: Sun Nov 02, 2008 9:18 pm Post subject: |
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| So that explains why I can read in the dark! |
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poopylungstuffing
Lolliwink Slayer
Joined: Mar 09, 2007
Age: 37
Posts: 7618
Location: Snapdragon Ridge
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| Posted: Sun Nov 02, 2008 10:17 pm Post subject: |
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This may sound idiotic, but can somepone please repost a link to the test? I am haivng trouble finding it...
Also....um....
i have a severe astigmatism...but i am reeely good at spotting stuff at thrift stores...I can really zoom in on goodstuff..just from seeing the edge of a pattern out of the corner of my eye...
One optometrist said my eyes were muscley...from spending so much time focusing without glasses.
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Danielismyname
Keep making noises... .
Joined: Apr 03, 2007
Posts: 9599
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| Posted: Sun Nov 02, 2008 10:31 pm Post subject: |
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VA: 1.04, Snellen fraction: 13/13
(I'm NT, I knew it.) |
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sartresue
Radical Aspergian
Joined: Dec 19, 2007
Posts: 6750
Location: The Castle of Shock and Awe-tism
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| Posted: Sun Nov 02, 2008 11:03 pm Post subject: |
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"Acuity so superior that it lies in the region reported for birds of prey " topic
That visual acuity would be superior to NTs is understandable. But the evidence and proof is now on record for posterity.
I would not go so far as to state that Autistics' vision is better than raptors, but on a par, in certain tests. I did not read the whole study, as my computer does not allow for viewing PDF files. For this reason I was unable to take the test. The HTML view does not have the test available.
However, in my IQ/skills tests there was a visual acuity section, and I far outperformed others according to percentile scores. The psychologist mentioned that this was because of my being on the Autistic Spectrum.
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Alisscious
Toucan
Joined: Oct 16, 2008
Posts: 263
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| Posted: Sun Nov 02, 2008 11:55 pm Post subject: |
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dec VA: 2.0, Snellen fraction:13/7
Threshold contrast 0.46%
vernier threshold: 0.03 arcmin
This is what I tested. So, um, heh. Sorry to sound redundant. WHat's it mean? lol |
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