Learn how to transpose an eyeglass prescription easily by learning a few simple rules!
Transposing a prescription is one of the most common actions when working in an optical laboratory, doctor’s office or even on a retail floor when an optician. Some eye doctors prescribe eyeglasses in what is called plus cylinder, and others do so in minus cylinder. Regardless of which is used, the prescriptions are the same. This can be proven by transposing the eyewear prescription.
1. Add the sphere and cylinder powers to determine the new sphere power.
2. Change the sign of the cylinder.
3. Change the axis by 90 degrees.
2. Change the sign of the cylinder.
3. Change the axis by 90 degrees.
Example 1:
Transpose 3.00 +2.00 x 30
 
Step 1

Add the sphere and cylinder powers to determine the new sphere power.

(3.00) + (+2.00) = 1.00

Step 2

Change the sign of the cylinder

2.00

Step 3

Change the axis by 90 degrees. (if the axis is 90 or less than 90, add 90 degrees to the axis, if the axis is greater than 90 deduct 90 from the axis)

120

The transposed prescription is: 1.00 2.00 x 120

Example 2:
Transpose 3.00 2.00 x 30
 
Step 1

Add the sphere and cylinder powers to determine the new sphere power.

(3.00) + (2.00) = 5.00

Step 2

Change the sign of the cylinder

+2.00

Step 3

Change the axis by 90 degrees. (if the axis is 90 or less than 90, add 90 degrees to the axis, if the axis is greater than 90 deduct 90 from the axis)

120

The transposed prescription is: 5.00 +2.00 x 120

Example 3:
Transpose +3.00 2.00 x 30
 
Step 1

Add the sphere and cylinder powers to determine the new sphere power.

(+3.00) + (2.00) = +1.00

Step 2

Change the sign of the cylinder

+2.00

Step 3

Change the axis by 90 degrees. (if the axis is 90 or less than 90, add 90 degrees to the axis, if the axis is greater than 90 deduct 90 from the axis)

120

The transposed prescription is: +1.00 +2.00 x 120

Example 4:
Transpose +3.00 +2.00 x 30
 
Step 1

Add the sphere and cylinder powers to determine the new sphere power.

(+3.00) + (+2.00) = +5.00

Step 2

Change the sign of the cylinder

2.00

Step 3

Change the axis by 90 degrees. (if the axis is 90 or less than 90, add 90 degrees to the axis, if the axis is greater than 90 deduct 90 from the axis)

120

The transposed prescription is: +5.00 2.00 x 120

credit: opticianworld, ehow, laramyk
+1.00/2.50 cyl 180
ReplyDelete1.5/+2.5*90
Delete4.00 X 180 how we do transposition for it ?
ReplyDelete4.00 X 180 how we do transposition for it ?
ReplyDelete4.00 × 180 is equal to 0.00 4.00 × 180
Deleteas per the above formula, transposed SPH will be (0.00 + 4.00)= 4.00
transposed CYL will be +4.00
and transposed axis will be (18090)= 90
it means the transposition for 4.00×180 will be 4.00 +4.00 ×90.
Whatbabout when You want to transpose a negative cylinder to plus, can You show a step by step. I like Your explanation.
ReplyDeleteWhatbabout when You want to transpose a negative cylinder to plus, can You show a step by step. I like Your explanation.
ReplyDeleteI have added three more different examples to understand more..Hope this will help you.
DeleteI like the way you are explaining except that for example in this one I can not understand it the spherical equivalent of (2.00+3.00 x090 why is the answer 0.50
ReplyDeleteanswer
DeleteThank you for the comment. But I couldn't find the power which you have said in your query?
DeleteIf you want to transpose 2.00+3.00x90;
Transposition will be: +1.00 3.00x180
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DeleteIf you want to transpose2.00+3.00×90; Transposition will be +1.003.00×90;on axis 90 to change opsosite to 180 ; an 180 axis change to 90 just simple Technique
Delete