An excellent and clear demonstration. I advocate prevention, before you go below 20/50, (self measured -1 Diopter), both eyes, but this is a valuable starting point for successful prevention. Thanks! I personally think that the person should be given the option of not being corrected for cylinder. As long as spherical provided 20/20.
A binocular blur balance would be a helpful step to add here, otherwise you are likely to force unequal accommodation and ultimately put the patient at risk of developing asthenopic symptoms.
I don’t understand how to use the Jackson cross. I never did that at my previous optometry job. I moved the cylinder knob, better 1 2, -.00 to -.50, if they said 2, I’d move the axis 45° each time better 1,2 then I’d end up at whatever axis and that would be it. That’s how I was taught to do it and I don’t understand why it’s wrong I really need help understanding this, please!!
Surprised they never really explain this stuff in the office, they just flip lenses around and give you a prescription would be nice to know what they're trying to do
When you see 50+ patients a day it’s really tough to do that unfortunately. Especially since usually when patients ask what you’re doing, it almost always pulls you into a huge slew of questions you just don’t have time for.
@@letlive113 yeah I mean imagine paying a teacher's salary and them not explaining what the hell they're talking about because they "don't have time", and a teacher drives a civic not a land rover
They see several patients daily. They don't have time to explain to every patient step by step what they are doing. They tell u the basics and really that's all u need to know.
Wish it was this simple. Unfortunately patients are human beings. Human beings make things complicated. Complicated things become an art. Art is perfected after a lot of painful refractions.
Thank you, this is interesting and valuable to me as a visually impaired person since birth. Because of my special condition (ocular albinism, optic nerve hypoplasia which resulted in horizontal nystagmus, and strong nearsightedness), my few attempts to get glasses at various ages were not successful. I honestly answered all the doctor's questions during the subjective refraction process and it felt good while at the doctor's office, looking at the charts and objects nearby. But when I received the final glasses, it always felt weird, the world felt unstable and my weaker eye felt like it had something wrong with it and I constantly wanted to blink it to "make it clear". At one point I got interested in optometry and I figured out that maybe doctors are prescribing too strong values. Maybe I could get used to them if I wore the glasses all day long, but as those were distance glasses, I wore them only occasionally. So I bought a set of cheap trial lenses and a frame. I started with the SPH and CYL values I received from my doctor from the refractometer and retinoscope. Then I adjusted the values down until I felt comfortable wearing the lenses for prolonged periods of time walking around my home looking at distant things and watching TV at a distance. Then I visited my doctor again to check if my results made sense and were safe and appropriate for my vision. She confirmed that it looks OK, although it is noticeably weaker than the full correction I would need. But if the full correction makes me feel uncomfortable, then it's OK to have the prescription with the values I came up with. And now I've been having my easy-feeling glasses for three years already. I can wear them everywhere I go without having any issues to accommodate both when I put them on and take them off. My experiments with the lenses led me to a few important discoveries. First, although technically my eyes have about 1D difference and would need different values, my brain has used so much to the fact that one eye is weaker so that it just cannot tolerate it when the correction is applied to attempt to make both eyes have the same final refraction. Then I feel like something's wrong and want to blink and clear my weaker eye. So, in my case, it's better to apply the same correction to both eyes. Then I don't feel any discomfort between my eyes. Second, my "vertical vision" is completely unfixable and unreliable. I just cannot see vertical lines in the astigmatism test, no matter what correction is applied, unless the lines are very far apart. Maybe because of the heavy astigmatism and horizontal nystagmus since birth, my brain just did not learn to distinguish vertical patterns well enough. I once found a study paper, where they seemed to come to the conclusion that for some visually impaired people orientation discrimination can be very bad in the vertical direction because of how their retina or brain works and prescription will not help much. In childhood, I rotated all books 90 degrees because that way it felt easier to read. It got better at the age of 8, and then I somehow started reading normally. So, for this reason, subjective refraction for astigmatism becomes tricky. Essentially, the doctor has to completely ignore everything I say about vertical lines because I just don't distinguish them at all at a distance. I might be able to perceive that "something's not right" when given lenses that make vertical astigmatism more pronounced, but I won't ever say "Oh, I see vertical lines worse now" (unless we talk about very near vision for reading). I'm not sure if all doctors have paid enough attention to this fact when doing subjective refraction on me. At least I don't remember any of them asking me about vertical lines specifically, so when asked which lenses make the image clearer for me, my answer was always based purely on the clarity of the horizontal lines only because the vertical ones were always too blurry to make any reasonable judgments. I hope the experience I shared will help some doctors better understand how a visually impaired person might see things and what caveats to look for when doing subjective refraction on such patients.
The content is very much helpful. I can say the best of its kind. But, as it keeps stopping throughout the clip, it makes things a little bit less attractive.
An AR? Would you actually prescribe a glasses Rx using one of those estimates? I use it for a starting point for a refraction through a phoropter, but they are often very inaccurate, or they can't find the centers/states no target, depending on the patient.
Thank you for taking the time to film this tutorial! It is very difficult while in training to find a good tutorial and you were thorough! My question would be however the circle of least confusion. I did not see an adjustment for that.
This was such a fantastic tutorial. Very informative, great production, and straight forward with visual aids. This has helped me so much with my refraction training!
