What’s the difference between the axis and power of a cylinder?
A cylinder power (the refracting power of a lens) is 90 degrees from the axis of the cylinder.
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A cylinder power (the refracting power of a lens) is 90 degrees from the axis of the cylinder.
wow,this is so cool for me as an optometry student,i learnt things so easily here,thanks.
truley well done …. i have learned soo much during my 1 st year ophthalmology residency from this great site!!
DEAR DOCTOR,
A PATIENT THAT NEEDED BI-FOCAL OR PROGRESSIVE LENS BUT HIS FAR VISION IS
SPH-1.50 CYL+0.50
NEAR VISION IS[READING GLASS]
+0.75
HOW CAN I PRISCRBE PROGRASSIVE FOR HIM.I DON’T KNOW HOW TO DO THE ADD FOR THE NEAR VISION.
Patrick,
Here’s how I would handle your prescription question:
1. The overall spherical power of a lens, is the sphere plus “half” of the cylinder power. In your case, that would equal -1.50 + 0.25 =
-1.25 spherical power for distance
2. Your patient likes his reading glass, which has a power of +0.75
3. The difference between his distance power (-1.25) and his reading power (+0.75) should be the power of his bifocal. Thus, your patient needs a +2.00 bifocal add.
4. I would write the final prescription as:
-1.50 +0.50 axis ?
Add: +2.00 bifocal
5. If you are putting in a progressive bifocal, you may want to add another quarter diopter to the bifocal (optional).
Good luck!
thank you very much for your answer but if the
far vision sph 0.00
near vision sph0.75(reading glass)
for his progressive the addtion will be written how?
can a man of 28yrs be prescribed progressive?
from patrick chris
today i have a patient 48YRS whos final prescrition is
(R)-0.25+1.75 axe45° (L) -0.50+1.75
ADD+2.25R&L).
she told me to make a reading glass for her because she can afford progressive.how can i prescribe reading glass or bi-focal glass for her? can a boy of 28 be prescribed for progressive?
from optician patrick chris.
thanks man ,I am residend of oph. by reading your site I got the thing. I mean your simplification method …do you bileave I did the same with our text AAOP ..I earn you man..
dear doctors I’d like to ask how can i transfer the optical equation feom @ (at) to axis ? for example this one : =
+0.5+1.0@90
i would like to write it by X axis not @
Thanks for the information,
I have a qustion,
Usually how much the difference of cylinder power between the two eyes of that a patient could stand?
..
Please mam tell me how to explain a patient what is the diffrence between spherical &cylinderixal power?
what is meant by 90 axis and 180 axis for distance vision and near vision. Are 90 or 180 axis are same for distance and near vision