I hadn’t planned on writing today, but a post by Rene in the forum warrants a quick look:
cm measurements:
RE: 21,0 cm
LE: 19,0 cm
Snellen 20/20:
RE: -4,75
LE: -5,25
Astigmatism test:
RE: All lines look nearly the same.
LE: 0°/10° lines look bold and grey.
90° line looks thin and black.
Eye examination, optic shop A:
RE: -5,50 +0,50 85°
LE: -6,00 +0,5 90°
Eye examination, optic shop B:
RE: -5.00 -0,50 160°
LE: -6,00 – 0,50 11°
These astigmatism corrections can’t be right.
With my trial lens set I found out:
RE: -0,25 160°
LE: -0,75 11°
—
85 degrees or 160 degrees? 90 degrees or 11 degrees?
If you have been visiting the blog for a while, you are of course aware of my position on most optometrist’s ability (or willingness) to correctly assess astigmatism. Just as Rene experienced, the results you tend to get are about equivalent to a stoned clown at a traveling circus spinning a giant wheel of astigmatism-fortune-prescription values. There are of course reliable ways to measure astigmatism, but they’re not commonly used by the strip mall optometry contingent.
I should have prefaced this article with a warning that it may not be the most measured in tone. Fraternizing with the more risqué type practitioners (Jake!) clearly has been having some questionable effects.
Let me illustrate the point above, and the optometric value of most astigmatism assessments:
And while of course the image isn’t a fair representation, the results that you are likely to get at the optometrist do reflect my opinion about astigmatism prescriptions.
The problem with unchecked astigmatism prescription is that it quite literally reshapes your eye, in a way that makes you more dependent on prescriptions.
The astigmatism prescription quite literally creates the problem, in more than a few cases. And equally damning (but fortunate), you can undo that same astigmatism prescription by managing your prescription needs more responsibly (or finding an optometrist who uses techniques to actually assess your astigmatism correctly).
Let’s look again at the two optic shop prescriptions that Rene received:
Eye examination, optic shop A:
RE: -5,50 +0,50 85°
LE: -6,00 +0,5 90°
Eye examination, optic shop B:
RE: -5.00 -0,50 160°
LE: -6,00 – 0,50 11°
vs. Rene’s own exam:
RE: -0,25 160°
LE: -0,75 11°
What you are looking at above is the second set of numbers for the amount of astigmatism correction, and the third row is the degree (where on the eye the correction is applied).
In my many astigmatism related articles I sometimes joke about how I might invent a magic eight ball (remember those?) to give optometrists yet another tool to accurately assess astigmatism prescription. And again, these whimsically created lenses they tell you to put in front of your eyes will create a focal plane stimulus, to which your eye will respond. In the end you will have a measurable problem that you didn’t have, at all, before you went to the optometrist in the first place. For the full thread of Rene’s topic, click here.
And as always, I must say that there isn’t any malice involved. Just as psychiatrist prescribe psychosomatic drugs like candy, and surgeons sell invasive procedures, so does the optometry field dispense diopter correction with total abandon. It’s the whole paradigm of health that is broken. The industry should never be run as a for-profit enterprise. Once you combine health and profit, this is exactly what happens.
As for astigmatism, I have a whole separate category of the blog dedicated to understanding the most important aspects of it.
Rene has the right approach. Measure diligently, and if you are dealing with a challenging case of astigmatism, invest in a test lens kit to get meaningful and accurate results for yourself.
Lastly, don’t follow my lead in terms of tone. There is no benefit to confronting or personally attacking anyone for their profession – the problem goes far beyond the optometrist, the school, and the lens maker. Everybody does the best they can, inside the broken system that is health for profit.
Hopefully you are enjoying some healthy eyesight today,
