Questions tagged [eye]
Questions related to diseases that affect the eye, visual acuity, lenses and glasses.
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Paper Interpretation, Determining permissible exposure limit of retina to light
I found a very interesting paper, that developed an empirical formula to calculate the MPE (s) (maximum permissible exposure limit) adapted to conditions that are common for desk lamps. You supposedly ...
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Can using glasses with a positive prescription when using a computer help prevent or minimize myopia?
I've seen multiple sources linking screen-time on a computer and myopia. If this is correct that exerting our eye-muscles causes this, would using glasses with a positive prescription prevent that?
...
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Evidence to support 20-20-20 rule?
American Optometric Association:
The average American worker spends seven hours a day on the computer either in the office or working from home. To help alleviate digital eyestrain, follow the 20-20-...
user27083
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Treating both Presbyopia and Myopia with LASIK/laser
So I suffer from Myopia. The degree is around 5-6. I also suffer from Presbyopia. I am 43 years old.
My doctor, one of the best in my region, says that my presbyopia cannot be corrected with surgery. ...
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Is it medically advisable to have spectacle lenses perfectly aligned with each other?
I have noticed some local brands of spectacles having the lenses slightly angled as shown in the second image below ("If lenses are at an angle"). I believe it is done to have the lenses ...
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Setting mobile brightness to match room light causes eye sight? [closed]
My son is watching mobile for many hours. I am not able to stop him as I am also working. He dont have any friends atleast to spend outside.
I just check his mobile and adjusts the briggtness to match ...
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Is iris shadow present in nornal eye?
As in immature cataract, there is lenticular opacity but there is an existing gap between the iris and anterior capsule of lens, hence iris shadow is casted owing to the underlying opacity that offers ...
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Health advantage of refractive surgery against shortsightedness and astigmatism?
As far as I understand, refractive surgery (eye laser surgery, intraocular lens) for fixing medium shortsightedness and astigmatism is only for comfort, because after the surgery you can probably see ...
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Quantitative retinal mosaic analysis corroborating better scotopic vision in colorblind individuals
According to https://www.sciencedirect.com/science/article/pii/S0042698997003398, color blind individuals have been shown to have an increased ability to see in very low light. Has there been any ...
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What are the effects on vision, of the breakdown of vitreous humour in eyes with age? [closed]
What would be the effects on the vision in an eye due to the breaking down of the eye's vitreous humour due to age? Going beyond just floater appearing, is there any effect on the optical ...
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Do monthly contact lenses have to be discarded 30 days from opening them even if they haven't been used? [closed]
I'm -8.00(OD) & -7.25(OS) and thinking of getting contacts lenses for the very first time. I plan on getting the monthly disposable type. I'll be wearing them once or twice a week mostly when I ...
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Is there a practical difference between glasses with astigmatism and short-sightedness adjustment versus glasses with only adjustment for the later?
I have astigmatism and short-sightedness. In your prescription they put several numbers to define how the lenses for your glasses should be built.
Your prescription can change over time, but I have ...
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What is the use of these green and red lines on Snellen/Eye chart?
I read that in eye tests red and green colors are used. For example:
But in Snellen/Eye chart, these are not background colors. These are lines only. What is the purpose of it?
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What would be visual acuity of a person if he can can read all letters of 20/25 and most of 20/20 on Snellen chart?
Suppose this is the Snellen chart:
And you measure your normal visual acuity using correct rules (i.e., placing it at 6 meters distance, in observation of an examiner in hospital.
And suppose you can ...
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Is there an objective method to know the degrees of nearsightedness or farsightedness?
Is there an objective method to know the degrees of nearsightedness or farsightedness? The current method for eye tests is to ask the patient to read numbers/letters, then the ophthalmologist puts ...
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Why do optometrists recommend dilation when the power of a lens can be measured even by a ruler?
I don't understand why optometrists dilate your eyes, which is a very annoying thing, when eye power can be measured by just a ruler at your home as suggested by this, which just uses a 100/(distance ...
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Home eye sight test for myopia patients? [closed]
I am a 16 year old and have been diagnosed with myopia since I was 8. I apologise for using wrong terms in advance, since I am not too familiar with medical terms. I wish to become a software engineer,...
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Is the common saying that sitting close to a screen regularly can cause short-sightednes backed by medical science?
How true is this? Should I be cautious as I spend too much time in front of a laptop screen? I already have glasses with power 0.5 and 0.25, ( this was 3 years ago, I haven't tested recently) but I ...
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Is it safe to see smartphone first thing in the morning? [closed]
Well, I'm a student and have many interesting things to learn, but not enough time. So, one thing I'm trying is that I pick one of the things that I really want to learn, but can't make time for, then ...
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Hyphema type that doesn't pool?
I'm gonna be honest here, I'm writing a story where a guy has the classical evil red eyes you can find everywhere, and I want to base it in science. I've thought about posting this on worldbuilding, ...
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Can colorblind people see any types of images that normally sighted people have a hard time with?
Could one devise a first image that contained a "hidden" sub-image where said sub-image is such that colorblind people would typically have an easier time seeing said sub-image embedded ...
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Why is monocular diplopia a symptom of astigmatism in some cases?
I have read that patients suffering from astigmatism sometimes experience monocular diplopia but I don't understand why this is.
Do we have an idea of why this occurs?
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Light adaption of pupil. When is a size adaption normal? [closed]
If an eye gets lighted with a flashlight or other light sources the pupils will decrease their width. This pupillary response is a typical indicator in diagnostics. Is there any specific value which ...
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How viral corneal ulcers due to HSV produce loss of sensation but painful at same time?
HSV= Herpes Simplex Virus
So, while reading about HSV keratitis I've come across a confusion,
Dendritic ulcers of HSV produce extremely irritating ulcer (Parson 22ed pg180)
dendritic ulcers of ...
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Is it harmful to touch/inhale soaked/liquid printer ink? [closed]
I have been printing a lot of work last night, but I accidentally placed my printed stack of paper (5 pages back to back filled printer ink) on top of a shelf below my air conditioner, next to me and ...
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Why do the eyes need to be closed during sleep to regain moisture?
I've noticed that if I don't sleep for a long time, my eyes get dry, and no amount of moisture helps to moisturize them. I moisturize every 10 minutes and it doesn't help. The answer is sleep. Our ...
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Can watching lightning be dangerous for one's eyesight (assuming not directly or indirectly hit by the lightning strike)?
Watching the sun can cause eye damage. Can watching lightning be dangerous for one's eyesight (assuming not directly or indirectly hit by the lightning strike)?
The only study I have found so far, {...
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What is "adaptive optics retinal imaging"?
A paper says
To validate the effectiveness of using A-GAN for data augmentation, we assessed its performance on cell analysis in adaptive optics retinal imaging, which is a rapidly-changing medical ...
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What is the difference between fundus image, fundus photography and retinal image?
I see these three terms in some papers in the field of medical images.
Google gives this kind of images for any of them, which indicates they pretty much mean the same thing.
Are they the same ...
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Meaning of colored ring around iris
There seem to be various conditions that affect the color of the outer edge of the iris, such as:
Fleischer ring - Wikipedia
Arcus senilis
Kayser–Fleischer ring
Limbal ring
and I imagine there are ...
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Can eyes really move "in and out"?
A tutorial says
outside of the globe or the orbit we can
see the ocular motor muscles which
control the movement of the eye those
control left-right up-down
in and out and allows the eye to ...
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medical meaning of "Meridian"
A video tutorial is using a spoon to explain how astigmatism occurs.
the cornea ideally
should be perfectly round like a
ping-pong ball which is a perfect sphere
and has the same curvature in ...
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How is micro debris cleaned from the eye in unusual cases?
Sometimes micro debris or "microparticles" are interacting with human's (and animals's) eyes:
It can be some types of dust or hair pieces trimmed with a trimmer; I especially mean little particles of ...
user8225
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Why can't we just close our eyes periodically to reduce eye strain?
The 20-20-20 rule I've heard is to stare at something 20 feet away, for 20 seconds, every 20 minutes to help reduce the strain of looking at things up close all day for those of us who need to look at ...
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Are focus-related eye diseases like myopia and astigmatism reversible? [closed]
Are those diseases recoverable without surgeries, glasses or contact lens? Maybe by eye exercises?
Edit: Once I saw on YouTube a man that managed to recover his eyes from these conditions by eye ...
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Can myopia be treated by applying pressure?
I have high myopia in my right eye (~7.00). I've noticed that unsystematically applying pressure onto certain areas of the eyelid onto the eye can actually bring the power down to about 3-5.00 (by ...
user17176
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Does the use of eye glasses prevent eye disease?
I'm turning 40 and went for my first eye test recently. They said I have nearsightedness. I work on a computer all day.
They gave me three quotes for eye glasses :
Option 1: (Cheapest price)
1.1 ...
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Is there a way to protect eyes from negative effects of computer and mobile screen? [duplicate]
People who work on computer and smartphone during most hours of the day are prone to impacts of the light of these screens. I have read about the negative effects of the light from screen. So I was ...
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How our brain discharge old CSF? [closed]
Our brain produces new CSF fluid every hour, so old CSF discharge from our body.
My question is where is CSF discharge point? or how our brain discharges Old CSF from the brain.
.
There is a ...
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Does corrective eye surgery for affect the ability to focus similar to corrective lenses?
If corrective lenses adjust the point at which the eyes focus and, for a strong correction, inhibit the ability to focus at the opposing distance, will corrective eye surgery affect vision in the same ...
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What is the name of a condition where one cannot/can poorly perceive depth for objects moving towards them
I remember a case where someone apparently had great difficulty perceiving the distance of an object if it was (quickly) travelling towards them. Their depth perception was otherwise fine, but when, ...
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What are the official eye colors?
In reading the wikipedia article on eye color, I noticed that the colors listed there seemed a bit arbitrary. Tangentially, I know that even the words we use today to recognize colors are neither old ...
user3495
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Does wearing UV blocking glasses worsen myopia in children?
I have found this article which claims (for chicken) that blocking outdoors UV light made myopia worse.
Some kids require glasses from a young age, e.g. 6 years old. Most of these glasses do have UV ...
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Eyelid thickness variation
I am working on a project in which I have to measure inter ocular pressure (IOP) of the eye. Currently, the gold standard to measure IOP is using goldmann applanation tonometer, in which anesthesia is ...
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Does playing wind instruments cause damage to the eyes overtime?
Found some studies that investigated the IOP's relation to wind instrument playing:
one two three.
I'm curious because I thought wind instrument playing (as over time it takes endurance to control ...
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What are those circles and lines I see when I squint at light?
what are those things I see? It happens when I look at a light source (Such as a light bulb) and the circles are supposed to be smaller on the picture. (I recreated what I see)
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Does staring at a screen for long periods of time cause myopia?
My uncle once told me "the real reason myopia happens because you look at a PC monitor non stop for hours. When you look to the same object for hours, the eye muscles gets used to the focusing close ...
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Is the increased intraocular pressure from playing wind instruments damaging to the eye?
People who play wind instruments often practice for hours every day. Some studies (this one as well) mentioned that intra-ocular pressure (IOP) raises during play. Some other studies measured a raise ...
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How to reduce the side effects of wearing contact lens? [closed]
This explains a lot of side effect of wearing contact lens. The type of contact lens Iam talking about is silicon hydrogel lenses.
Questions:
1) Till how many hours can lens be worn continuously?
2)...
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Abnormal shrinkage of the eyeball
Is there a condition which describes an abnormal shrinkage of the eyeball?
That is, a counterpart to buphthalmos (an abnormal enlargement of the eyeball).
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