Prescriptions and what they mean....

[Lynn White]

Well this is what I am getting to hehe....

The sph means sphere - the basic long or shortsighted bit, cyl means how much astigmatism you have and the axis is what angle that astigmatism is at.

So...
sph cyl axis
say we have plano / -1.00 x 180


This means the eye has -1.00D of shortsightedness vertically and zero power horizontally. The axis is always the angle of minimum power.

So if we had -3.00/-1.00 x 180 and you imagine a cross representing the power meridians of the eye, the vertical power line would be -4.00 and the horizontal power line would be -3.00.

When we test eyes, the trial frame would have in a spherical lens of -3.00, correcting the basic shortsightedness, and in another cell of the frame there would be a lens with zero power along the horizontal and -1.00DS along the vertical. ie different powers along different meridans....

Now, its not unusual for someone with KC to have powers of -16.00/-5.00 x 20 or -2.00/-6.00 x 90 - and I saw a KC patient today who was only -0.75/-1.00 x 80, so REALLY you can't generalise. However, I know what you are getting at and a really advanced KC is more likely to be up in the region of the first example.

The average shortsightedness in the general population is up to about -4.00 with varying amounts of astigmatism. However, I myself am -7.50/-1.25 x 110 and I am not KC (though I do have a relative who is, but whose prescription is not as bad as mine!)

[Alison Fisher]

Okay, my right eye is +1.75 -4.75 109 and my left +2.50 -3.50 120 (if I can read my optician's handwriting correctly that is ), and I think, if I remember rightly, that I can just about read the third from the bottom row of letters.

And now I'm going to re-read this thread again. I think I'll need a new packet of choccie biccies.

[Sweet]

Lynn

The diagrams helps loads and i now understand more, it now all makes sense!! I don't get a lot of things by just reading and need some pics and diagrams to help me visualise it.

Hehe John don't go on about a tube map as i don't know where i'm going unless i can see it!!

As i have never used glasses with any success i'll take some time out to read the contact lens post later.

Thanks for explaining it in nice pics for me as it doesn't matter what language you use i'll always get lost! Although your last post did lose me again, maybe i need to print your pics and try again!:D

Sweet X x X

[Lynn White]

Yeah...

I reckon I need more pics.,.. groooan!

Will be working on it... but not till after easter!

[Andrew MacLean]

Lynn

by the end of this we'll be telling our optometrists what our readings are!

Andrew

[Sweet]

Hehe well knowledge has never been a bad thing!!

Sweet X x X

[Lisa Nixon]

It's really helpful to read all this. I know my left eye is worsening slowly, but it has been ever since the stitches came out 2 yrs ago and I'm concerned that it might just continue to deteriorate. I've noticed I'm having to turn my head more and more to get the right bit of the glasses lens to focus through. Looks like I'm leering!

[Andrew MacLean]

Lisa

What does your ophthamologist say? any word of your wearing lenses again?

Andrew

Sweet did yu eat that egg. or have you just hidden it from Gareth and me?

[Sweet]

Hehe no the egg is still there, though soon it will have to sadly leave as Easter will be over!!

Sweet X x X

[Lynn White]

Just bumping this up to see if anyone has any other queries??

I'll gradually start putting this together as a FAQ with diagrams - or is that better as an article John?