I missed my lecture on this. This is a life saver, thanks.
@IqbalKathrada3 жыл бұрын
Wish you were my lecturer in university Ian.
@nonexistenty41524 жыл бұрын
Thank you for this informative video. It is extremely helpful for me
@MrThecrazyzombie Жыл бұрын
my left ear enjoyed this
@CuriousDrifter4 ай бұрын
It seems to me that in order to do the reversal test, a -0.25 cylinder at 100 deg (perpendicular to the original sharpest line) should be added, instead of a -0.25 sphere. Because the former would be an over-correction, causing the anterior focal line to go further back, becoming the new posterior focal line, thus causing a reversal, while the latter would just move the entire pencil closer to the retina, therefore shouldn't cause a reversal. Am I missing something?
@abibridge26034 жыл бұрын
We use minus spheres to activate accommodation for Cross Cyl, can you/anyone explain why this is important in terms of the COLC and focal points?
@ash1982ification5 жыл бұрын
Hello sir kindly upload a video on fogging method. Thanks
@dharshanakumar8 жыл бұрын
Hi Ian,sorry it may sound silly,cant you put +0.50 with spare (to bring 2nd focal point infront of ret) before even turn on fan and bloack chart?
@abduomo98459 жыл бұрын
i just did nt got whay Alen started with +1.Is it because u have + ve prescription or is something that we have to do prior to fan and block. appreciate any help
@abduomo98459 жыл бұрын
+Ian Squire many thanx ur videos are hepling me a lot in my optometry education.
@modathirreads-5517 жыл бұрын
From Sudan, thanks a lot.
@namithavijayan48813 жыл бұрын
Anyone pls tell me how he choose that 100degree axis and why he turn the arrow in clockwise direction...plss
@aleksandraszczepanik80523 жыл бұрын
Very clear explanation. Thank you!
@erikahmadhasyim97686 жыл бұрын
i'm sorry sir, can i get explanation about how you determined the X is 100, Thank you for your great video
@kapilhrathaur0077 жыл бұрын
sir plz also explain in new video madox rod and worth 4 dot test and glare test.
@deepuv91504 жыл бұрын
I confused with adding minus power.
@sabithavibash51253 жыл бұрын
Thank you soooooooooo much Sir
@wefaqalssaqaf97248 жыл бұрын
i donot understand the axis chosen
@wefaqalssaqaf97248 жыл бұрын
+Ian Squire thank you so much i think i got it now
@saff1257 Жыл бұрын
principle: Find BVS with a subjective or ret test. bring 2nd FL to ret with pos. bring 1st FL to ret with neg. test: occlude one eye. use BVS fo estimate the cyl power, add half the pos cyl to get 2nd FL onto ret. adjust the axis. (at 90* to test chart axis). add 0.5 sph plus as a check for later. now onto blocks. need to add minus cyl until blocks are equally blurred. the check: remove the 0.5 sph and there should be a reversal of block clarity.