optical prescriptions

[Bernice]

I had my eyes tested (first time in France) with the opthalmogue, the figures on the prescription seem very different from those on my UK prescription made out a year ago.  (The French opthalmo checked my glasses and said my sight hadn't changed)  Do they have a different way of writing out the prescriptions? 

Bernice

[Will]

I understand that the way of writing prescriptions for spectacles is indeed different, though contact lens prescriptons look virtually identical. Many French opticians seem able to understand English prescriptions, so things cannot be that different, but there is always a danger of getting it wrong of course.

[Spicy]

In the UK and worldwide the optical prescription can be written in two forms depending on where the optometrist/ophthalmologist trained.

If you look at the cyl part it can have a plus or a minus infront of the number - think of those as different languages that you need to transpose (translate) before comparing.

It's easier if you post your prescription here for me to transpose for you to compare.

To try yourself:

you add the sph and cyl together (remembering the signs)

change the sign of the cyl

change the axis by 90 (add or subtract - maximum number 180) (we use 180 instead of 0)

so: -5.00/-1.00x60 becomes -6.00/+1.00x170

or +3.00/+1.50x120 becomes +4.50/-1.50x30

[Will]

Thanks for that, you learn something new every day. It certainly explains why some English prescriptions are wrongly interpreted in France, and vice versa.

[Bernice]

Thanks Spicy - I'll go and have a good look at the two prescriptions and compare them.  I'll report back [:)]

Bernice

[Bernice]

Hi Spicy

I've scanned my prescriptions to jpg images - what next?  Do I need your email address?  Can I post them on the forum?

Thanks for your help

Bernice

[Spicy]

Bernice YHM