2 ways of reaching the same eye prescription?!
Question: 2 ways of reaching the same eye prescription!?
Hi
Had my eyes tested today, and the optician said that there had not been much change in my vision since my previous test!.
However, when I got home, I found my last prescription!.!.!.!.
Todays:
Right - Sph -0!.75, Cyl -0!.75 Ax 90
Left - Sph -2!.25, Cyl -0!.50, Ax 85
Last test:
Right - Sph -1!.25, Cyl +0!.75, Ax 180
Left - Sph -3!.00, Cyl +0!.50, Ax 170
Now, to me, they look totally different!. So, are there 2 ways of achieving the same result, or has someone made a boo-boo!?
The optician took readings on her equipment of my current glasses, which are around 4 years old!. Could she have made a note of this by mistake!?
Thanks for reading!Www@Answer-Health@Com
Had my eyes tested today, and the optician said that there had not been much change in my vision since my previous test!.
However, when I got home, I found my last prescription!.!.!.!.
Todays:
Right - Sph -0!.75, Cyl -0!.75 Ax 90
Left - Sph -2!.25, Cyl -0!.50, Ax 85
Last test:
Right - Sph -1!.25, Cyl +0!.75, Ax 180
Left - Sph -3!.00, Cyl +0!.50, Ax 170
Now, to me, they look totally different!. So, are there 2 ways of achieving the same result, or has someone made a boo-boo!?
The optician took readings on her equipment of my current glasses, which are around 4 years old!. Could she have made a note of this by mistake!?
Thanks for reading!Www@Answer-Health@Com
Answers:
Your myopia has increased by -0!.25 in each eye from the last test!. The rest of the prescription is pretty much the same!.
You are being confused because there are two ways of writing the same prescription called "plus-cyl" and "minus-cyl" forms; you have one of each type!.
To convert between the two, add the cyl to the sphere, add (or subtract) 90 from the axis (don't go over 180), then change the sign of the cyl!.
To conver your right eye from today's test to plus-cyl form!.!.!.
add the cyl to the sphere -0!.75 + -0!.75 = -1!.50
add 90 to the axis = 180
change the sign of the -0!.75 cyl = +0!.75
gives the result -1!.50 / +0!.75 x 180
As you can see this is -0!.25 more sphere than last time!. If you think you can notice the change in your vision from the last test, you should get some new glasses made up to the new prescription!.
Try converting the left eye!
Www@Answer-Health@Com
You are being confused because there are two ways of writing the same prescription called "plus-cyl" and "minus-cyl" forms; you have one of each type!.
To convert between the two, add the cyl to the sphere, add (or subtract) 90 from the axis (don't go over 180), then change the sign of the cyl!.
To conver your right eye from today's test to plus-cyl form!.!.!.
add the cyl to the sphere -0!.75 + -0!.75 = -1!.50
add 90 to the axis = 180
change the sign of the -0!.75 cyl = +0!.75
gives the result -1!.50 / +0!.75 x 180
As you can see this is -0!.25 more sphere than last time!. If you think you can notice the change in your vision from the last test, you should get some new glasses made up to the new prescription!.
Try converting the left eye!
Www@Answer-Health@Com
There are two different ways to write these, you are right!. Today's test is written in minus cylinder form:
Todays:
Right - Sph -0!.75, Cyl -0!.75 Ax 90
Left - Sph -2!.25, Cyl -0!.50, Ax 85
Your older one was written in pouls cylinder form!. If I write the Last test (The older one) in minus cylinder it would look like this:
Right Sph-0!.75, Cly -0!.75, Ax90
Left- Sph -2!.50, Cyl -0!.50, Ax 80
So, your right eye stayed the same and your left eye changed minimally!. Some people would notice this change, some would not!. It is very minor!.Www@Answer-Health@Com
Todays:
Right - Sph -0!.75, Cyl -0!.75 Ax 90
Left - Sph -2!.25, Cyl -0!.50, Ax 85
Your older one was written in pouls cylinder form!. If I write the Last test (The older one) in minus cylinder it would look like this:
Right Sph-0!.75, Cly -0!.75, Ax90
Left- Sph -2!.50, Cyl -0!.50, Ax 80
So, your right eye stayed the same and your left eye changed minimally!. Some people would notice this change, some would not!. It is very minor!.Www@Answer-Health@Com
Re: spectacle man above
You have made a mistake in transposing the R eye of the last test!.
The accurate transposition is:
R Sph -0!.50 Cyl -0!.75 Ax 90
This means the eye has not stayed the same but has increased by -0!.25 Sph as Martin stated above!.Www@Answer-Health@Com
You have made a mistake in transposing the R eye of the last test!.
The accurate transposition is:
R Sph -0!.50 Cyl -0!.75 Ax 90
This means the eye has not stayed the same but has increased by -0!.25 Sph as Martin stated above!.Www@Answer-Health@Com