At what distance do you hold the phone for the test? There HAS to be a set distance! If it is less than 20 feet, it is not a valid test, unless you have an intervening lens to compensate for not being at 20 feet (or 6 meters).
Great videos! Thank u! Only want to add… there is no +3 etc…. It’s 20/30- (meaning -1) 20/40+(meaning +1) or -2/+2 If someone gets 3 wrong or right… it moves To documenting the line above or below. So 20/30-3 is actually 20/40+2
This is correct under the assumption that the chart has 5 letter lines. In the event of a 6 letter line chart the principle is similar; if you get half correct, move to the next line. If a patient read three out of six letters on the 20/20 line then none on 20/15, in that case acuity would be 20/20-3.
@@arturotheburro what if they got one in the 20/15 but 20/20-3…. I wonder if most projectors have odd number of letters. I haven’t paid attention bc it’s so automatic for me now. I have only memorized the old school fzbd4, oflc3, slides
@@ChicagoChicago27 It would be the same notation, you could write 20/20-3/+1. Same as if someone read 3 20/20 and one 20/15 line on a 5 letter chart would be 20/20-2/+1. This is really semantics though haha. In clinic I don’t often denote +/- unless there’s a specific difficulty or something with the vision.
