You guys have no idea how much you are helping tons of optometric students out here... These primary topics are the most important and essential part in Optometry practice. Thanks for the good work. Please make more...
Happy to help. We have a library of videos coming over the coming months (every Friday). If you are an AOP member you can get access to our entire library today www.aop.org.uk/ot/cpd/education-library there you can also see many other resources that wont be coming to TH-cam
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.
You guys have no idea how much you are helping tons of optometric students out here... These primary topics are the most important and essential part in Optometry practice. Thanks for the good work. Please make more...
Happy to help. We have a library of videos coming over the coming months (every Friday). If you are an AOP member you can get access to our entire library today www.aop.org.uk/ot/cpd/education-library there you can also see many other resources that wont be coming to TH-cam
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.
Thanks!
Thanks , what if patient is compound hypodermic astigmatism is this procedure?
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