now before we begin the refraction it's very important that we select you
the appropriate trial frame after taking the interpupillary
distance measurement so available today we have these wonderful
trial frames
the blue trial frame here we have the black beautiful black we have a bright yellow
we have the green here and the pink at the top
they all go up in two millimeter increments so before we place the trial frame on you
we need to take the interpillary distance measurement so we're going to use this ruler here
excellent i'll just get it set up for you
okay so i need to be on your eye line i'm going to rest the ruler just and the forehead here
okay just looking into this eye please and this eye
so we have a reading of 62 millimeters between the two eyes
let's have a look which frame that correlates to 62 millimeters
oh yes 62 millimeters is the yellow trial frame here
so this is the trial frame i'll be using today
a 62 millimeter setting the distance between the center of the hole is that 62 millimeters
lenses will be perfect for your optical centers let's take the frame out the case for you
you have to be very delicate very careful
wow there we go
here is your brand new yellow trial frame for your refraction pop this on in a moment we'll perform
some retinoscopy i'll do some with or without the lens lens one or two so let's have a little look
there is your new trial frame we have
three areas here so we can hold three lenses in place potentially
and those grooves there the metal supports here we also have a slot at the rear of the frame
if we need to place some lenses there
the length to bend is preset from there but these have a wrap around
design so they'll stay on your face much more easily so we won't have to do any adjustments
to the sides of the frame there we also have the twizzle here for rotating lenses
when we're checking your astigmatism i'm checking your astigmatic element a astigmatic element
and you have the scale here so we can align
the cylinder at the correct axis that gives you the best vision
okay so let's get the trial frame on and perform some retinoscopy for you
okay so now that the trial frame is sitting on you comfortably we need to place a plus 1.5
dioptre sphere lens in place just to do some retinoscopy okay so we'll pop this
in the trial frame the vision might go a little bit blurry there do not fear
okay just looking
into the distance while i have a little look with the retinoscope
i'm just sweeping the light in different meridians
and maybe changing the lens around
okay i just want to place a plus 2 dioptre lens into the frame
let's just move the trial frame across on you there we go
okay
keep looking into the distance please
okay i'm just going to reduce this to a plus one seven five
keep looking to the distance just turn your head slightly please good
this should be the last lens we need to try
excellent okay
let's just remove this lens here
okay let's pop the room lights back on
good okay so i think we should do some subjective a subjective refraction showing you some lenses
to see if we can make the letters a little bit clearer for you okay okay so as you're
looking at the letter chart what is the smallest row you can read for me please
and the next row down if possible
just read that row left to right for me now okay as you're looking at that row i'm going to present
some lenses just tell me if that row is clear with or without lens so that's with or clearer without
okay let's try the next lens
and the smallest row you can see sharper with the lens or without
without excellent okay we'll leave that one out
okay let's try some different powered lens is the smallest row you can see clear with the lens
or without let's with or without
okay i'll place that lens in if it's a little bit clearer there we go excellent let's just pop it in
there excellent a little bit sharper with the lens in place excellent
let's show you this minus 0-fifty dioptre sphere is the smallest row sharper with the lens
without better with
or without with without slightly without excellent
let's just drop that down and go for a minus 0-25 dioptre sphere
is the smallest row cleared with the lens without or about the same it's with
without
with without excellent okay we'll change that lens in the frame for you
so now we have a minus 0.75 dioptre sphere
there we go i'm just going to reverse things a little bit
with the plus lengths this should be a little bit worse
so is the vision a little bit more blurry with compared to without
slightly without excellent that's what we wanted
now this is a very fine plus 0.25 dioptre sphere should be a little
bit worse in theory but let's see it's the smallest row you see clear with the lens
or without that's with or without maybe slightly with okay we can reduce
the sphere in the frame there
that's fine
so we've landed on a minus 0.50
diopter sphere there excellent okay now we're going to move on to some cross cylinder
so essentially this is using the jackson cross cylinder here to check if there is a little
bit of astigmatism in your prescription which is essentially rugby ball-shaped eyes so that is the
minus 0.25 jackson cross cyl flipper lens so your job is to keep your eye
on the round 'O' at the top of the chart i'll show you two lenses one after the other
and you tell me which one you feel is the clearest or if it's about the same okay so looking at the
'O' clearer with lens one or lens two it's one two or about the same one two slightly two that's fine
so we're going to pop a minus 0.25 dioptre cylinder into the frame for you there
across there excellent still looking at the 'O' is it clearer with lens one
or two so one or two just move to the left a little bit please there we go
good keep your head there try not to move okay and now is the 'O' clearer with lens one
or two one or two what about the same good let's check
from this angle now is the 'O' clearer with lens one
or lens two one two okay i'll rotate the lens there
and again is the 'O' clearer with lens one two lens two excellent okay so it looks as though
we have a prescription of minus 0.50 dioptre sphere with a minus 0.25 diameter cylinder
at 145 degrees there excellent excellent okay just relax for a second
now we're going to do a little near vision test with some more with or without the lens
okay i'm going to use this little test chart here up close
okay i need to know what is the smallest print you can read on the page for me please
excellent excellent
okay let's move on to the next near vision chart i have the
shamir near vision chart a little bit different to more specific text so what is the smallest print
you can read down to please on the chart
it's very small at the bottom okay so maybe here just a bit
excellent so we have a size of n5 excellent now to ask you to look at the n5 print
i'll show you some more lenses you tell me if the print is clearer with or without
so we just have a small plus out 0.50 dioptre sphere here okay looking at n5 is it clearer
with the lens or without with without or about the same with without excellent excellent
let's just see what the plus one dioptre sphere does for you so again focusing on the print here
is it clearer with the lens or without with
that fantastic i'll leave that one out and we'll try one more lens
plus 0.25 there might not be much difference here i just want to confirm
is that print clearer with or without the lens with without excellence okay
i think we have the results of the refraction there
thank you very much for coming into the clinic that's all we need