My question: Is it necessary and absolute that the first meridian which we clear on stenopic slit is the axis meridian and the second one is power meridian, my point is that what is the logic, concept and reason behind this, why the second meridian can't be the axis meridian.. Hope sir you will clear this doubt
Hello sir, can i ask a doubt. Is this method only for minus cylinder. Or we have to take transposition . If plus cyl also possible, then can u explain me with one example.
Why do we want to rotate the stenopic slit from 90 to 180. ? So i can say straight away like in which axis patient sees clear image that is his/her axis meridian rite? I dont understand sir. Can you please explain it?
How to assume Fogging lense +1.50 any reason is this working distance lense or -2.00 and +1.50 difference 0.50 suppose the sphere part should +3.00 the fogging lense is -2.50sphere or what
Hello sir thank u Please there is something I can't understand first when u worked on axis 90 u put minus 2 sphere then fogged u till plus one so the total minus one and your final prescription didn't go that way
If we're moving from -1.5 to - 1 What's the cylindrical power? Do we take the signs in consideration when moving from high to low?? So in the example I mentioned ,-1 is bigger than -1.5 But if we don't take the signs in consideration, then 1.5 is bigger than 1
In this scenario we take sign of cyl in consideration..in this video we are actually reducing and moving from +1.50 to +1.00 so power of cyl would be 0.50 and sign would be minus, because we are moving from bigger plus to lesser plus..so we actually moving towards minis direction so sign would be in minus.
Sir please resolve my two queries. Q1. If we reduce the cylinder value in prescription, will axis remain same or it will also changes by some degrees like 10°-15°? for eg., if we reduce cylinder from this prescription -1.00/-0.75 axis_35° (left eye) to -1.00/-0.50, what would be the new axis-? Q2. Eye testing computer machine (Auto Refractometer) in optician shop give this reading :- -1.00/-0.50 axis_161° (right eye), -1.00/-0.75 axis_38° (left eye). And the optometrist of the shop give this prescription by using digital Phoropter device and digital display chart :- -1.00/-0.50 axis_160° (right eye), -1.00/-0.50 axis_20° (left eye). Why he reduced the left eye axis from 38° to 20° but not the selected nearby axis like 30° or 25° ? Isn't 18° cylindrical axis variation is high and outside the safe tolerance limit ? [ Few days ago, I also checked my eyes from the hospital, and their auto refractometer give -1.25/-0.75 axis_37° (for left eye) and the doctor gave prescription -1.25/-0.50 axis_30° (left eye). ]
Answer 2: Your auto refractometer is not always correct, If autoref gives any power or axis a good optometrist should verify thiese power and axis with some manual techniques like hit and trial method and he must go with the patient comfortable axis not the machine..because in Asian countries like India, Pakistan, Bangladesh people always used the autorefs are not of very good quality, these machines could be good some times or some times they gives wrong prescription. So that's why an optometrist always relies on his/her skills not on machines. Hope it's clear.
By increasing or decreasing the cylindrical power the axis always remains the same..if they are already correct. It doesn't make any difference in axis either you are increasing or decreasing the cyl power.
My dear.. Our cylinder was -0.75..not +0.75 Because when we reduce fog from axis meredianwhich was 90 degree.. the remaining fog was +1.00..and when we change the axis of slot 90 apart at 180 degree..and reduce the fog +0.25 To get the cylinder we moved from one principal axis meredian to other principal power meredian..mean from +1.00 to +0.25 ...and resultant value i -0.75..because we actually moved from bigger plus to lesser value..so the sign is in minus. And our axis meredian were at 90 degrees so our correct axis were 90...not 180. Hope you are clear.
Aslam o alaikum respected sir ! sir i have a two question if you give me permission to ask ! first one is that why we add fog lens of +1.50 instead at the end we substract +0.25 from +1.00 why wr do not substract +0.25 from +1.50 bcz we add fog lens +1.50 and if we substract from +1.00 then why we do not add +1.00 at first initial step ! please guide me ..
We add fogging lens so we relax all accommodation of the patient, and then we we reduce fog from both of the meredians from power and axis meredians as well.. To get the correct power and axis.. Of cyl.
dear sir i have a one question regarding astigmatism, i have gone to different eye doctors but still they were not able to solve my problme. in the night with/without the glass i see a virtical lines or a kind of distorted/blurred little bigger shadow of street lights/light bulbs/moon and shadows of white letters in black background. i am even using dry eye drops as a doctor suggested that i might have dry eyes.. now i am so confused please suggest me something to do
@@rajshreerajput4290 dear.. you need a complete eye checkup..go for a slit lamp examination..for vitreous and fundus. I wish I can personally check your eyes..but consult with best ophthalmologist.
Sir please create a video on Borish delayed technique and borish delayed spherical end point. your video is very much helpful fot my studies. thank you.
I am myopic , in the correction of refractive error in my right eye is getting a problem , my rt eye power is -1.25 and if I keep -1.25 , and it getting blur , - 1.50 also some blur , now what's the problem , is i am astigmatism ? Can you tell ?
Mr. venu gopal, i wish i can make a eye test for you.. yes its possible there must be some astigmatic correction you reqyured. you need a proper eye test.
@@optometrywithkhurram6867 sir , today I gone through eye test , in that my right eye ( cylindrical power increase sir , one year back -1.25 , now it is -2.25 , ) and my left eye is same as last year power no change , ,,,,,,. Is it possible in one year -1 cylindrical power increase in my right eye , please tell me sir ??????👀
since the prescription is -2 -0.75 90 degree (-2.75 90 -2 180), wouldn't the best acuity have been achieved with the slit at 90 without a positive lens and with a -0.75 lens when slit is at 180 degree? i mean why to stop at +1 and +0.25 when defogging?. just a noob there, thanks for explanation!
Respected sir second question is for my guide line please guide me can we do subjective refraction is this case by refining axis of cylinder by stenopic slit 90 degree can we add cyclinder by step of _0.25 at 90 degree at maximum best vision correction . Is this method is true or not please guide me i shall be very thank ful to you
Yes.. It's fine.. You can do it as well.. You can put a least power of Cyl before the patient's eye and rotate 360 degree to get the proper axis and then you can enhance the power of the cyl.. To get correct power.
I am a student of Optometry, so I have some questions..... can you please help me? 1) What if there is no fog left after the axis was rotated 2) The fog is being reduced.... so the sign will be - for the cyl power, when can it be + cyl power?
Smart questions 👍 No.1 If there is no fog left then it means fog will b zero then we will move from 1st value to zero ...and that will be our cylinder. No.2 In this case sign of cyl will always in minus because we are moving from bigger fog value (+1.00) to lesser fog value (+.25) so we are actually moving towards minus direction. So cyl would always be in minus. If you want it in plus you can simply transpose the final prescription.🙃
@@optometrywithkhurram6867 Okay sir thank you very much😄 and I really appreciate your hard work and how you are replying to each comment and question asked in all your videos. Thank you
Sir please explain that why we start fogging method with 1.50 dsph? secondly, why are we stopped with +1.00 dsph with principal meridian? what we do if the patient subjective refraction is +2.00 Dsph not minus spherical? very good lecture. please help me for understanding about that questions.Thank you sir.
Answer of your 1st question. We apply fogging lenses of +1.50 Dsp because we need maximum blur to relax accommodation. Afte placing the fogging lens before the patient's eye 2 to 3 lines should be blurred.and +1.5 create 2,3 lines blurred so that's why we use 1.5 plus sphere as our fogging lens. And our main concern is to relax accommodation. Hope this is answer the question. 😊
Answer of your 2nd question. You know that there are two principal meredians in astigmatism, and we have to reduce the fog from both of the meredians, and we will reduce the fog until unless the patient gets maximum visual acuity, if we reduce all the fog from both of meredians it's means patient is not astigmatic. So it's confirm if patient is astigmatic then patient will prefer any value like +1.00 or +0.75 Etc depends on the clarity. And same as the other meredian.
Answer of 3rd question. Yes we apply same procedure of best vision sphere is with Minus or + sphere. Hope all is clear 👍 Dear sanchita basu If you still got any confusion you can contact us on whtsapp.
Good day doctor, thank you for this informative video. I just have a question. You mentioned that we stop reducing the fogging lens until we reach clarity. When you say clarity, do you mean we should reach the 6/9 acuity? Thank you.
Welcome..as you know that in astigmatism we have always two principal meredians ..one for axis and other for power..so our 1st meredians was axis meredian and we have to reduce the fog to gain the correct power their and we will reduce the power untill patient accept the reduction..and then we will rotate the axis 90 apart and will approach the power meredian and we will again reduce the for until we get maximum visual acuity ..
@@optometrywithkhurram6867 Oh I get it... So not necessarily 6/9. Just the best acuity we can get from reduction. Thank you very much doctor. I appreciate your response.
Sir how we can understand that this or that patient need stenopic slit correction for astigmatism ? & How we can understand that which patient is astigmatic
Dear.. Avinanda.. In astigmatism patient needs cylindrical correction, if yor patient is not having 6/6 visual acuity with just spherical lenses.. And all media of the eye (lens, cornea, aqueous and vitreous) is transparent and clear.. Then you must try the cylindrical lenses. And with stenopic slit you can treat small degree of Astigmatism easily. Hope this is answer the question. You can suggest any video.. You want. 🌸👍
I have watched many videos of yours all was great and clearly explained but this video is not clear bcz why you are start putting +1.5 sph you could also start with +2sph and also putting numbers different different + sph plz make clear video sir.Not expected
There is a logic behind every happening.. And the reason behind this is.. If a person having VA 6/6 wear +1.50 DS as fogging lenses then his VA would be worst upto 6/18..it means a fog lens of +1.50 make 3 to 4 lines blurred.. In this procedure we will use fog lens of +1.50 to make 3,4 lines blurred and in every binocular balancing techniques we always use this fogging lens to relax accommodation.. As well.. Hope it's clear.
If i were still in my optometry school years ..you' re surely be my favorite prof..you teach very well..
Thank you so very much dear.
You can also refer optometry with keertika , she also explains very well
My question:
Is it necessary and absolute that the first meridian which we clear on stenopic slit is the axis meridian and the second one is power meridian, my point is that what is the logic, concept and reason behind this, why the second meridian can't be the axis meridian.. Hope sir you will clear this doubt
Hello sir, can i ask a doubt.
Is this method only for minus cylinder.
Or we have to take transposition .
If plus cyl also possible, then can u explain me with one example.
Why do we reduce fogging lens 1.50 to 1.25 ? Why can't we increase it ? Please ans
Why do we want to rotate the stenopic slit from 90 to 180. ?
So i can say straight away like in which axis patient sees clear image that is his/her axis meridian rite?
I dont understand sir. Can you please explain it?
How to assume Fogging lense +1.50 any reason is this working distance lense or -2.00 and +1.50 difference 0.50 suppose the sphere part should +3.00 the fogging lense is -2.50sphere or what
Hello sir thank u
Please there is something I can't understand first when u worked on axis 90 u put minus 2 sphere then fogged u till plus one so the total minus one and your final prescription didn't go that way
In refraction : Sph: plano and High cyl -5.00 D. For example..... IT is possible to aply this method?.
As far as this video is concerned..it's about for minor cylinder
Fir high cyl ..will upload a new video
Sir , is fogging is applicable for higher level of astigmatism if it is -4D cylinder correction how can we do fogging in this case
Thanks dear sir g .....very good explanation 😊❤
Why do we write 90 degree axis at prescription ?
If we're moving from -1.5 to - 1
What's the cylindrical power?
Do we take the signs in consideration when moving from high to low??
So in the example I mentioned ,-1 is bigger than -1.5
But if we don't take the signs in consideration, then 1.5 is bigger than 1
In this scenario we take sign of cyl in consideration..in this video we are actually reducing and moving from +1.50 to +1.00 so power of cyl would be 0.50 and sign would be minus, because we are moving from bigger plus to lesser plus..so we actually moving towards minis direction so sign would be in minus.
How to find Fogging lense according to sphere part whatever it minus or plus always Fogging lense +1.50 or other
Sir please resolve my two queries.
Q1. If we reduce the cylinder value in prescription, will axis remain same or it will also changes by some degrees like 10°-15°?
for eg., if we reduce cylinder from this prescription -1.00/-0.75 axis_35° (left eye) to -1.00/-0.50, what would be the new axis-?
Q2. Eye testing computer machine (Auto Refractometer) in optician shop give this reading :-
-1.00/-0.50 axis_161° (right eye),
-1.00/-0.75 axis_38° (left eye).
And the optometrist of the shop give this prescription by using digital Phoropter device and digital display chart :-
-1.00/-0.50 axis_160° (right eye),
-1.00/-0.50 axis_20° (left eye).
Why he reduced the left eye axis from 38° to 20° but not the selected nearby axis like 30° or 25° ?
Isn't 18° cylindrical axis variation is high and outside the safe tolerance limit ?
[ Few days ago, I also checked my eyes from the hospital, and their auto refractometer give -1.25/-0.75 axis_37° (for left eye) and the doctor gave prescription -1.25/-0.50 axis_30° (left eye). ]
Answer 1:
If our axis are totally refined and best corrected then either we increase or decrease the power of the cylinder our axis must be the same.
Answer 2:
Your auto refractometer is not always correct,
If autoref gives any power or axis a good optometrist should verify thiese power and axis with some manual techniques like hit and trial method and he must go with the patient comfortable axis not the machine..because in Asian countries like India, Pakistan, Bangladesh people always used the autorefs are not of very good quality, these machines could be good some times or some times they gives wrong prescription.
So that's why an optometrist always relies on his/her skills not on machines.
Hope it's clear.
By increasing or decreasing the cylindrical power the axis always remains the same..if they are already correct.
It doesn't make any difference in axis either you are increasing or decreasing the cyl power.
How about adding a +1.00 lens to blur the vision? Must it be +1.50 please?
Yes you can use +1.00DS as well .but it depends on spherical power..👍
Hi sir, how to determine the fogging lens?
Is there a calculation?
From the video i heard that the BVS VA was 6/9
Sir my question is the cylinder power we got at the end +0.75 D , but why are we putting the axis 90 instead of 180?
My dear..
Our cylinder was -0.75..not +0.75
Because when we reduce fog from axis meredianwhich was 90 degree.. the remaining fog was +1.00..and when we change the axis of slot 90 apart at 180 degree..and reduce the fog +0.25
To get the cylinder we moved from one principal axis meredian to other principal power meredian..mean from +1.00 to +0.25 ...and resultant value i -0.75..because we actually moved from bigger plus to lesser value..so the sign is in minus.
And our axis meredian were at 90 degrees so our correct axis were 90...not 180.
Hope you are clear.
@@optometrywithkhurram6867 okay sir now it's clear to me, thank you ✨
@@priyodarshiniii good
Aslam o alaikum respected sir ! sir i have a two question if you give me permission to ask ! first one is that why we add fog lens of +1.50 instead at the end we substract +0.25 from +1.00 why wr do not substract +0.25 from +1.50 bcz we add fog lens +1.50 and if we substract from +1.00 then why we do not add +1.00 at first initial step ! please guide me ..
We add fogging lens so we relax all accommodation of the patient, and then we we reduce fog from both of the meredians from power and axis meredians as well.. To get the correct power and axis.. Of cyl.
dear sir i have a one question regarding astigmatism, i have gone to different eye doctors but still they were not able to solve my problme.
in the night with/without the glass i see a virtical lines or a kind of distorted/blurred little bigger shadow of street lights/light bulbs/moon and shadows of white letters in black background. i am even using dry eye drops as a doctor suggested that i might have dry eyes..
now i am so confused please suggest me something to do
Kindly share your age..and share If You have any ocular or medical history..
@@optometrywithkhurram6867 i am 27 and i dont have any medical history sir
@@rajshreerajput4290 dear.. you need a complete eye checkup..go for a slit lamp examination..for vitreous and fundus.
I wish I can personally check your eyes..but consult with best ophthalmologist.
Sir please create a video on Borish delayed technique and borish delayed spherical end point. your video is very much helpful fot my studies. thank you.
It's a great suggestion..
Sure u will upload a video on this topic. 😊😊
I am myopic , in the correction of refractive error in my right eye is getting a problem , my rt eye power is -1.25 and if I keep -1.25 , and it getting blur , - 1.50 also some blur , now what's the problem , is i am astigmatism ?
Can you tell ?
Mr. venu gopal, i wish i can make a eye test for you.. yes its possible there must be some astigmatic correction you reqyured. you need a proper eye test.
@@optometrywithkhurram6867 sir , today I gone through eye test , in that my right eye ( cylindrical power increase sir , one year back -1.25 , now it is -2.25 , ) and my left eye is same as last year power no change , ,,,,,,. Is it possible in one year -1 cylindrical power increase in my right eye , please tell me sir ??????👀
@@venugopalrao98 yes..its not a big deal..it can increase..but if you consult a credible optometrist.
since the prescription is -2 -0.75 90 degree (-2.75 90 -2 180), wouldn't the best acuity have been achieved with the slit at 90 without a positive lens and with a -0.75 lens when slit is at 180 degree? i mean why to stop at +1 and +0.25 when defogging?.
just a noob there, thanks for explanation!
Sir what is the use of fan and dial method in stenopeic slit?? or this is separate test?
Both are different techniques.
Respected sir second question is for my guide line please guide me can we do subjective refraction is this case by refining axis of cylinder by stenopic slit 90 degree can we add cyclinder by step of _0.25 at 90 degree at maximum best vision correction . Is this method is true or not please guide me i shall be very thank ful to you
Yes.. It's fine.. You can do it as well.. You can put a least power of Cyl before the patient's eye and rotate 360 degree to get the proper axis and then you can enhance the power of the cyl.. To get correct power.
I am a student of Optometry, so I have some questions..... can you please help me?
1) What if there is no fog left after the axis was rotated
2) The fog is being reduced.... so the sign will be - for the cyl power, when can it be + cyl power?
Smart questions 👍
No.1
If there is no fog left then it means fog will b zero then we will move from 1st value to zero ...and that will be our cylinder.
No.2
In this case sign of cyl will always in minus because we are moving from bigger fog value (+1.00) to lesser fog value (+.25) so we are actually moving towards minus direction. So cyl would always be in minus.
If you want it in plus you can simply transpose the final prescription.🙃
@@optometrywithkhurram6867 Okay sir thank you very much😄 and I really appreciate your hard work and how you are replying to each comment and question asked in all your videos. Thank you
@@saptarsighosh welcome ..dear..you are such a brilliant student..keep it up.
@@optometrywithkhurram6867 Yeah sure thank you😄 you keep up the great work too!
@@saptarsighosh 🌸🌸🙃
You are really good!
Tnq so much ,simply super explanation
So nice of you... Keep watching
That's clear sir👌
Welcome
With plus lens fogging we first add and then remove previous lenses not the vice versa
in Binocular balancing we add fogging lenses and the add or remove extra fogg for balancing dear.
Sir pls tell me about astigmatism fan test
Sir please explain that why we start fogging method with 1.50 dsph? secondly, why are we stopped with +1.00 dsph with principal meridian? what we do if the patient subjective refraction is +2.00 Dsph not minus spherical? very good lecture. please help me for understanding about that questions.Thank you sir.
Answer of your 1st question.
We apply fogging lenses of +1.50 Dsp because we need maximum blur to relax accommodation.
Afte placing the fogging lens before the patient's eye 2 to 3 lines should be blurred.and +1.5 create 2,3 lines blurred so that's why we use 1.5 plus sphere as our fogging lens.
And our main concern is to relax accommodation.
Hope this is answer the question.
😊
Answer of your 2nd question.
You know that there are two principal meredians in astigmatism, and we have to reduce the fog from both of the meredians, and we will reduce the fog until unless the patient gets maximum visual acuity, if we reduce all the fog from both of meredians it's means patient is not astigmatic.
So it's confirm if patient is astigmatic then patient will prefer any value like +1.00 or +0.75
Etc depends on the clarity.
And same as the other meredian.
@@optometrywithkhurram6867 thnku sir
Answer of 3rd question.
Yes we apply same procedure of best vision sphere is with Minus or + sphere.
Hope all is clear 👍
Dear sanchita basu If you still got any confusion you can contact us on whtsapp.
Thanks sir❤❤❤
Sir in Hindi
Sure
And when u worked on 180 axis final was fogging by plus. 25 on sphere minus 2 so total minus 1.75
Good day doctor, thank you for this informative video. I just have a question. You mentioned that we stop reducing the fogging lens until we reach clarity. When you say clarity, do you mean we should reach the 6/9 acuity? Thank you.
Welcome..as you know that in astigmatism we have always two principal meredians ..one for axis and other for power..so our 1st meredians was axis meredian and we have to reduce the fog to gain the correct power their and we will reduce the power untill patient accept the reduction..and then we will rotate the axis 90 apart and will approach the power meredian and we will again reduce the for until we get maximum visual acuity ..
@@optometrywithkhurram6867 Oh I get it... So not necessarily 6/9. Just the best acuity we can get from reduction. Thank you very much doctor. I appreciate your response.
@@kimcruz1894 you are welcome Kim.🌸
Why people use this If they have cross cyl?
It's just a method to rule out astigmatism of low power...
Sir how we can understand that this or that patient need stenopic slit correction for astigmatism ? & How we can understand that which patient is astigmatic
Dear.. Avinanda..
In astigmatism patient needs cylindrical correction, if yor patient is not having 6/6 visual acuity with just spherical lenses.. And all media of the eye (lens, cornea, aqueous and vitreous) is transparent and clear.. Then you must try the cylindrical lenses.
And with stenopic slit you can treat small degree of Astigmatism easily.
Hope this is answer the question.
You can suggest any video.. You want. 🌸👍
I can't understand 😢
But why should we fog the patient . we can also perform this without fogging.
No dear.. SONU.. We can't do this without fogging the eye. 👍👍
Excellent!
Thankyou..
how to get +/- power
its depends on patient;s condition
Thank you 🙏
You’re welcome 😊
Thank you, Sir. Thoroughly Explained :)
Most welcome iqra.
Wow. Wow.. No More struggles
Keep watching.. And you can suggest any topic 👍
Hi, this is so informative thank you!! What exactly is a meridian?
Very nice sir
Thankyou..🌸
👍 thank you
Thank you too
I have watched many videos of yours all was great and clearly explained but this video is not clear bcz why you are start putting +1.5 sph you could also start with +2sph and also putting numbers different different + sph plz make clear video sir.Not expected
There is a logic behind every happening.. And the reason behind this is.. If a person having VA 6/6 wear +1.50 DS as fogging lenses then his VA would be worst upto 6/18..it means a fog lens of +1.50 make 3 to 4 lines blurred..
In this procedure we will use fog lens of +1.50 to make 3,4 lines blurred and in every binocular balancing techniques we always use this fogging lens to relax accommodation.. As well.. Hope it's clear.
@@optometrywithkhurram6867 Thankyou so much for your reply sir
Great sir
Thankyou Adil keep watching 💯
You're the best yooo ❤
Thank you sir
You are welcome
❤ ❤❤
I m so confused I do t think I can learn refraction ever
Ohh my dear.. What confusion do you have?? Let me know..i can help you..
👍❤️
Keep watching
Treat
🌸
🥰
👍👍
Your defogging are wrong
Study hard son.
Not remove 1.50 without put 1.25 plus lens
During defogg
Sir kindly urdu ya hindi me kr lia krein 😂
Which topic you want in Urdu?
@@optometrywithkhurram6867 sir ap k sab topics interesting hoty hn sir❤
@@optometrywithkhurram6867 transposition aur priscription card k bary me
@@mfaizan4485 I already have videos on these topics but in English..soon will make videos on these topics in Urdu.
@@optometrywithkhurram6867 Thankyou so much ❤