Can anyone decipher opticians figures?

Nine_Lives

Trying to find my old results to see how they compare.
I'm having a bit of bother with headaches which i'm due to see the GP for. Went for an eye test as i figured GP would say to do that. My results are this...

Right:

SPH = +0.75
CYL = -1.50
AXIS = 105.0

Left:

SPH = +0.25
CYL = -0.75
AXIS = 75.0

It was only after i left that i really wondered what these figures actually meant & exactly how much of a difference in real world terms they mean.

tidus

What are you comparing that to? You've only posted one prescription.
As to what it means, you have a fairly low amount of hypermetropia (long sightedness) combined with a fairly low amount of astigmatism. The right eye is slightly worse.

Only you can really quantify the difference your prescription makes to you. I'd recommend that prescription for driving, TV, and near tasks. It should make everything clearer, but not so much that you can't manage without some of the time.

Nine_Lives

tidus wrote: »

What are you comparing that to?

The left to the right really. Just wondered how much of a difference there was as the numbers mean nothing to me really. Just a curiosity thing that's all.

I do have my old one somewhere & when i find it i'll post back.

And you're right - when my eyes get tired, i find i need the glasses for reading. Some times the computer screen isn't all that clear if my eyes have gotten quite tired, so i'll need them then, but for the most part i'm fine.



EDIT:

Well, haven't found mine yet, but the wife found hers.

She was born after 22/24 weeks (i forget which) which resulted in her being pretty much blind in her right eye, which will explain the results slightly:

Right:

0.00 (for everything)

Left:

SPH = -0.25
CYL = +0.25
AXIS = 100.0

Bit of a difference from mine. I always have to rely on her when viewing things really far away as she's generally quite good at it.

Pennywise2012

Your wife's prescription in the left eye is barely anything, really. To interpret it, here's a long and boring lesson -

Imagine your glasses lens with a crosshair over it. Your prescription measures the power of the lens along the horizontal line, and the vertical line. If there is a difference between the two lines, you have astigmatism and your prescription will have a cyl and an axis. If not, you will just have a value for the SPH (sphere) and it will have DS written after it. (dioptre sphere. Dioptres are the 0.25 steps the power of the lens is measured in)

SPH - The start of the prescription. Can be either the vertical or the horizontal line of the crosshair, doesn't matter. A + sign in front is for hypermetropia (so a person would be able to see distance OK but struggle close up) and a - sign is for myopia (see up close OK but struggle for distance). The higher the number, the stronger the prescription, so the more benefit felt by the wearer.

CYL - if the second line of the crosshair has a different prescription. It's recorded as the difference from the SPH, so the +/- indicates whether the power is higher or lower on the scale, rather than long/short sightedness.

AXIS - you only have this if you have a CYL. It's a measurement in degrees, and is basically how much the crosshair needs to be rotated by. It's always between 1 and 180, but because it's just the angle, 1 is no better or worse than 180 - the lens is still the same power.

When writing a prescription down, it doesn't matter whether you start with the horizontal line or the vertical line as the SPH, as long as you change the axis by 90 degrees. For example

SPH -6.00 CYL +1.50 AXIS 95

is exactly the same as

SPH -4.50 CYL -1.50 AXIS 5

So, for your own right eye, the SPH is +0.75 (bit longsighted). The CYL is -1.50, so because that is the difference, the power there is -0.75 (bit shortsighted). It would also be correct to write your prescription as SPH -0.75 CYL +1.50 AXIS 15. As Tidus says, glasses would sharpen things up for distance and close work, but you wouldn't normally be dependant on them 24/7.

For your wife's sighted eye, the SPH is -0.25, so a tiny bit shortsighted along one crosshair. The CYL is +0.25, so that means there is no prescription along the other crosshair. It's literally the smallest prescription you can have, and it would be unusual for her to wear glasses to correct it.

Well, that turned out longer than I was expecting!

Nine_Lives

Thanks very much for going into detail. Very helpful.

So then ... you'd be surprised that when she visited an optician in Scotland before she moved, she was given a prescription for specs to help her sore head/tired eyes.
She came down to an opticians here who said she totally does not need glasses.


As you seem to know a thing or two....

I have 2 glasses. 1 set of normal & 1 set tinted (sunglasses).

When wearing the clear ones, it always seems to take a bit of tie for my eyes to adjust.
Not only this but if wearing them for a good few hours, they can (can, but not always) end up hurting my eyes.

When wearing the sunglasses set, my eyes take a hell of a lot longer to adjust. I can move my head & it's like my eyes are playing catchup.

Is all that normal? I've only had glasses for the past 2 years.