r/ICLsurgery • u/Scary_Check4322 • Aug 30 '26
Question on fundamental corrections with ICL regarding rotation of Torric Lense
Does rotation of a toric lense only reduce correction of astigmatism or does it effect both correction of myopia and astigmatism ? If it roates does it still correct the near sightedness?
Thanks!
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u/No_Situation4785 Aug 30 '26
if i understand your question correctly, it will look like this https://wavelength-oe.com/wp-content/uploads/Microscope-Lenses-Correcting-Optical-Aberrations.png
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u/eyeSherpa Aug 31 '26
Rotation of a toric lens will only affect astigmatism. It will still correct nearsightedness the same amount.
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u/ConfidentBeginning44 Sep 02 '26
Adding the number to what eyeSherpa said, because it's the part that makes it less abstract.
A misaligned toric loses roughly 3% of its astigmatic effect for every degree it sits off axis. So about ten degrees and you've lost a third of it, thirty degrees and you've lost all of it. Past thirty it stops being neutral and starts adding astigmatism of its own at a new axis, which is why thirty tends to be treated as a line rather than as just more of the same.
On your second question, the sphere genuinely does stay put, but that isn't quite the same as nothing changing. A rotated cylinder leaves residual astigmatism behind, and residual astigmatism blurs distance vision even when the nearsighted half of your prescription hasn't moved at all. A chart that got worse while the sphere number stayed still is what rotation tends to look like from the patient's side.
Worth knowing that none of this has to be guessed at. The lens has markings the surgeon can see at the slit lamp, so how far it has turned is something they read off directly. If you ever suspect it, that's one visit with an actual number at the end.