scilearner Posted October 19, 2014 Posted October 19, 2014 (edited) Hello everyone, I have this friend who has a slight strabismus. His eyes look away from me when speaking, but that means he is actually looking at me. I can understand how these people, brains may learn to ignore certain images and adapt to this condition. But how can his eyes physically look away from me, and still see me. Also in a case where both eyes are crossed, wouldn't it be almost impossible to see properly. Thank you Edited October 19, 2014 by scilearner
Endy0816 Posted October 19, 2014 Posted October 19, 2014 (edited) Uncorrected my eyes cross. Initial effect is simply my nose being mirrored. Right side is on the left and vice versa. There is something of a "see through" effect that also occurs. Staring at a particular side of my nose I also see what is behind it at the same time. Something like a transparency or image layer effect. For myself at least one eye normally dominates and I don't tend to see doubled images(though easy to do so if I choose to). It's weird, I'm reading about people not seeing their own nose without closing an eye and being shocked later in life when it "suddenly" begins appearing in their regular vision. Live and learn. Edited October 19, 2014 by Endy0816 1
Endy0816 Posted October 22, 2014 Posted October 22, 2014 (edited) Based this off of the self portrait done by Ernst Mach(yes, that Mach). Think it shows most of the effects quite nicely. In reality only the area that overlaps would have doubled imagery and reversed sides of the nose in the field of vision. Related if a 360 of the topic title, how exactly do people "normally" see their nose(or not)? I found accounts online but not much in the way of description of what exactly is being observed. Edited October 22, 2014 by Endy0816
davidivad Posted October 22, 2014 Posted October 22, 2014 they have a blind spot... i used to leverage this on a cooworker by jumping out of a trash cart when she was looking right at me with that one eye...
Xalatan Posted January 23, 2016 Posted January 23, 2016 In children, the brain is relatively plastic, so it learns to switch off vision processing from one eye as adaptation to diplopia. This is why if strabismus is not corrected in children it leads to amblyopia. In adults a squint will cause double vision. There are specially designed prism glasses that correct the angle of incident light hitting the affected eye as means for correction. Hilary Clinton wears them. http://www.theblaze.com/wp-content/uploads/2013/01/clinton-fresnel-prism-glasses-620x446.jpg Surgery can also correct strabismus.
Function Posted January 23, 2016 Posted January 23, 2016 The phenomenon Xalatan is talking about is called "suppression scotoma", it generally is the neglecting by the brain of visual input from the affected eye (be it an eye showing strabismus, or perhaps amblyopia ex anopsia ['lazy eye']), if the healthy eye (you can appreciate that if the healthy eye is covered, of course your brain will not start neglecting visual input from the affected eye) is not covered by an eyepatch during the 'critical period' of development of cortical plasticity
michel123456 Posted January 24, 2016 Posted January 24, 2016 (edited) Based this off of the self portrait done by Ernst Mach(yes, that Mach). Think it shows most of the effects quite nicely. In reality only the area that overlaps would have doubled imagery and reversed sides of the nose in the field of vision. Related if a 360 of the topic title, how exactly do people "normally" see their nose(or not)? I found accounts online but not much in the way of description of what exactly is being observed. Ernst Mach did not suffer from strabism as far as I know. The self portarait is a picture of himself with his right eye closed. The picture on your post is a mirrored image created by you I suppose. A search in Google about Ernst Mach Self returned your picture in 4th place and I am afraid may bring misunderstanding to the Internet community. Not to say the peculiar result of superposing the curve of his nose. Edited January 24, 2016 by michel123456
Endy0816 Posted January 24, 2016 Posted January 24, 2016 (edited) Sorry, thought that it was clear that I used his image to produce that one. I included his drawing in the spoiler below it. A search in Google about Ernst Mach Self returned your picture in 4th place and I am afraid may bring misunderstanding to the Internet community. Not to say the peculiar result of superposing the curve of his nose. That's funny, I hope most would recognize the use of image editing software though. Not to say the peculiar result of superposing the curve of his nose. Looks normal to me... Edit: Seriously I do know what you mean. The sort of "cyclops look" resulting from the overlap. How the world looks to me without my glasses though. For the longest time I thought all artists were employing artistic license in their paintings and drawings by not adding in their own noses. Live and learn. Anyways good to understand IMO, at the very least because it is entirely possible for strabismus to develop later in life. Hopefully helps people understand what is going on and that they can see an optometrist for assistance in dealing with the underlying problem. Edited January 25, 2016 by Endy0816
Externet Posted January 25, 2016 Posted January 25, 2016 A subject of extreme interest to me. My daughter was born with strabismus; had her first eye muscle surgery at about six months new. And several after. Wore alternating eye patch at the beginning, Fresnel lenses later. The point was to prevent amblyopia, and keep both eyes active even without stereovision. She avoids driving as conscious of the impairment, but says she sees well. A comment to expect as she has never seen in stereo. Took her to the best opthalmologists in the planet. It is a brain problem, by the optic nerve chiasm, inoperable as far as I understood. I designed and built electronic LCD shutter glasses to provoke the no-loss of sight in the non-dominant eye, and were shown/presented to professionals of the specialty before use. All agreed that would not do any harm but of unknown therapeutic results as such thing was never tried nor exist before ~1995. I pushed my daughter to wear them while watching TV. She did not loss the use of any eye, but am not claiming due to wearing the glasses. The shutter glasses were taken to Germany for evaluation by specialists, and their interest somehow faded, lost track. Still have them, prototypes and finals, if anyone has the urge to borrow these, specially for a kid under 11 years old, I will gladly share them. Contact is my username at inorbitdotcom Would like to see a drawing as in post #3 by Endy but made by someone with that condition, or a clear explanation.
Endy0816 Posted January 27, 2016 Posted January 27, 2016 (edited) Pretty impressive work. Considering working effectively solo especially so. May be an idea to ask your daughter what she sees rather than how. Most would answer in terms of clarity(which probably is really good for her). Aside: Could anyone with normal vision please tell me what they see of their face(both eyes open, staring straight ahead)? I've read that it is not seen normally(various explanations given), but would like some confirmation from a reliable source. Edited January 27, 2016 by Endy0816
michel123456 Posted January 29, 2016 Posted January 29, 2016 Pretty impressive work. Considering working effectively solo especially so. May be an idea to ask your daughter what she sees rather than how. Most would answer in terms of clarity(which probably is really good for her). Aside: Could anyone with normal vision please tell me what they see of their face(both eyes open, staring straight ahead)? I've read that it is not seen normally(various explanations given), but would like some confirmation from a reliable source. To me: Without effort, both eyes open and looking straight ahead I see nothing from my face. When I close one eye, the nose appears in a blur. When I look at it, it appears like in the sketch you posted. Both eyes open and looking straight ahead I cannot tell with precision where my vision ends left & right. I get the impression that my memory plays a role because I "feel" what is behind me although I cannot see it.
Endy0816 Posted January 30, 2016 Posted January 30, 2016 (edited) To me: Without effort, both eyes open and looking straight ahead I see nothing from my face. When I close one eye, the nose appears in a blur. When I look at it, it appears like in the sketch you posted. Both eyes open and looking straight ahead I cannot tell with precision where my vision ends left & right. I get the impression that my memory plays a role because I "feel" what is behind me although I cannot see it. Thank you. First coherent explanation I've seen online. I see the same thing with one eye closed. What I see with both eyes open, are the two normally separate(one eye closed views) at the same time. An engineering way to think of it would be in terms of camera feeds. Imagine two filming the same area, but then imagine one feed placed partially on top the other. If things were nicely lined up, everything would be fine. If they were not then you would see doubling and similar oddities like the flipped nose. You should see a similar transparency-like effect by watching a video on your phone when placed right up to one eye. Like that for my nose. Really would have issues if things were otherwise, nose is almost always in view. Edited January 30, 2016 by Endy0816
michel123456 Posted January 30, 2016 Posted January 30, 2016 (edited) After thinking a little more about it I get more and more the impression that all senses are mixed. While I look ahead, I also hear the sounds reflecting from everywhere, I feel the cold from the window behind and I "know" where I am (I use my memory & all experiences before). I am not like suddenly awake and tied on a chair, not being able to know where I am, wearing blinkers with the head fixed straight somehow, completely deaf. That would be a creepy situation. Edited January 30, 2016 by michel123456
Endy0816 Posted December 4, 2017 Posted December 4, 2017 (edited) Wondering if actual correction might be possible via camera feeds. Number of variables but seems feasible. Edited December 4, 2017 by Endy0816 Mental Note: When replying don't forget what you yourself wrote
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