Binocular Balancing and Reading Pescription
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- čas přidán 7. 11. 2015
- After the BVS has been achieved monocularly the eyes have to be balanced to work together comfortably. This video demonstrates a simple fogging technique used to do this. After this the reading addition was assessed. This fogging method should be done at the end of the sight test so in the case of a thorough cross cyl examination this should be done after the astigmatic correction has been assessed. In the video I was keeping it brief and only did BVS followed by the binocular balancing and reading prescription.
- Krátké a kreslené filmy
u're videos are helping me a lot. since im very new with optometry. thank you. keep uploading this kinda of video sir
Good discussion of BVS, and sequence.
I like your videos as they are very much to the point. Thank you for your work. Considering binocular balance I do prefer to dissociate left and right eye, preferably with polarized test (my viewchart projector allows for this) or with prisms. I find it easier for patients to spot the difference, as the +0,75dpt fogging is often not enough to easily differentiate.
For the addition I think your lighting is way too dim I use small desk lamp that I hold over reading chart so my patients have properly lit text for this test. With less light our depth of field causes patients to prefer over-correction (hence higher image magnification) in order to compensate for the impaired contrast.
thank you for the information
can i know why you didnt do cylinder? isnt the procedure is from BVS to determining cylinder for astigmatism and lastly binocular balancing?
Thank you so much
Thank you
Are there any downsides to doing a prism dissociative balance like most docs do today? I had a doc do a prism dissociative test and they found a diff of 0.25 sph in my eyes but another doc that didn’t do bin balancing found -1.5 in my left and -0.75 in my right which is a much greater diff
Good video
it's a very interesting video,thnx a lot.
this video is old but i want to ask anyway, so what if adding the -0.25 lens does make it better for the patient? Do we keep it?
I had a doc balance me after monocular refraction to best vision by holding up a single plastic frame device with a single +0.25 (I think) lens in each eye and asking me if that made any difference to the chart letters. I said no it did not. The doc therefore _concluded_ that with this balancing test, the mono prescription can safely be _reduced_ by 0.25 with no loss of clarity. Is this correct?? She did not do a "blur one eye fist" balancing test. Is this correct??? Thanks Dr. Squire/others...
0.25 not important refraction error
What if patient has only cylinder? What we do with presbyopia? We check with cylinder or without...
You need to first be sure there is no spasm of accomodation in that cylinder. That is done by keratometer. And of course modern way to check vision is cylinder first. So the opposite of what is done in this video. Why? Because it is harder to check the opposite way, cylinder is very sensetive.
What if initial prescription had no minus spherical lenses in both eyes(plano in both eyes) and his prescription contains only cyl
That is harder to tell, because that may be astigmatism but it also can be spasm of accomodation. You need a kerato- capable meter to check whether lens have any fake astigmatism.
我剛在全家等爸爸時 我一直打電話 問事情 我問大舅舅 跟我想到有兒子的才會幫助我 我請文章先生布袋戲的幫我跟媽媽說 我需要比0.5G 還多的網路 i just wait for my father in we are family convenience store i ask my big uncle and i suddenly think that if a person has a son so he will help me to solve my problem
i ask 文章 who play the hand puppets to have a bargain with my allowance which is my income and saving money from i am an elementary school student i save 5 NT every day because i didnt eat egg cookies
Thanks Dr Squire! Give the client a newspaper first. That finds their preferred reading distance for everyday items. All optometrists should have one handy in the room! Reading is as much about comfortable posture of arms as much as it is about clarity. Just first giving them the test chart with 10 different fonts is confusing to both parties and when he says "oh, that's much better" - for which size of text - he didn't say or was told which to evaluate?! Go to the test card after finding their preferred reading distance (for a book; different for a PC). And do a newspaper check after. The doctor is not pausing long enough after the client's answers to let him speak more, but kind of assuming he knows what the client is thinking (saying "right" right as the patient is answering?!). I wouldn't like this style of optometrist. As a patient, I need a bit of time to say and/or correct my judgements, not be forced into them in any way. I'm an experimental psychologist, not an optometrist, but I have high myopia and I think about these issues as I want the doc to get it right, and I want him to know I know he got it right (ie, agree).
You are right, the factors you described explain pretty much why doctors failed to find correct reading glasses for my needs. Here's what happened.
I have congenital ocular albinism, optic nerve hypoplasia and slight horizontal nystagmus. Because of these issues, my vision is very bad. I can see only the first two lines with my left eye and only the first line with my right eye. Things get especially blurry in distance. When reading books and using computer screen, I bring the item much closer (15 - 30cm, depending on text size) than healthy people do to be able to read the text, and even then I sometimes have to use magnifying glasses.
I understand that these conditions cannot be helped much and I do not hope on wonders. Still, I hoped that it should be possible at least to reduce the blur. It turned to be correct - the doctor found out that I have also myopic astigmatism, so lenses up to -1D help me to see more clearly in distance without straining my eyes, and adding some cyl correction of -2D at 170 degree axis helps even more. I'm satisfied with my distance glasses.
But with reading glasses it was a total failure. The doctor saw how I'm reading small newspaper letters with eyes strained, so he added +1.5D to my neutral (with 0 sphere equivalent) cyl prescription. Initially I was glad - hey, now I see the small text better! But when I tried to read computer screen or text books, it all was messed up because of my reading distance differences, depending on text size. When the text is large enough, I move my head further, and now those +1.5 diopters actually make my eyes feel worse. I guess, there is some strange accomodation going on in my eye where at some point my eye doesn't need those + diopters any more and actually feel worse, maybe because my myopia kicks in.
Initially I didn't know much about optometry. I just was disappointed with my two failed attempts to get reading glasses. It was important for me because I work as a programmer.
Then I read some good books about the subject and watched some videos and bought a trial frame and some lenses from China and started experimenting. I started with correction that does only astigmatism correction to collapse my Sturm's conoid without affecting my focus as such. With lenses of +1sph and -2cyl I get 0 sph equivalent and my eyes feel noticeable improvement (sharper text) in both distance and reading and I don't feel so wrong as with my failed reading glasses when I attempt to read on computer screen. Still, it's doesn't feel a definite solution because my eyes don't feel as easy as when reading without the trial lenses, so I added +0.25 to make it better (and possibly less overminused at some areas in my eyes from those cyl lenses). It's currently very tricky - on one hand, reading feels better and sharper, on the other hand I feel some eyestrain but I'm not sure if it's from my choice of lenses or because of the fact that the trial frame is heavy, the lenses have limited field of view with rings around them and also because they are not as clean as glasses, no matter how I attempt to clean them (slight mist accumulates when you combine more than one lens in the trial frame - it's never as clear as final spectacles).
So yeah, it's very tricky. I'm just trying to avoid spending money on new spectacles that would make me feel worse. Maybe I'll have to give up and accept the fact that it's impossible to find correction for reading, despite the fact that astigmatism correction works in general. Somehow my eyes don't like it at closer distances, although they like it at large distances. I'm not sure what more can be done here and what kinds of experiments should I try, considering that two doctors failed to achieve even those best results that I achieved myself.
But were u not suppose to do cross cyl first before Binocular balancing...??
En u weren't suppose to do balancing if their VA between two eyes is more 2 lines
Are u an optometrist
That is modern way of doing it, yes.