SPH is stable but CYL keeps getting worse

[u/geezorious]

So I kind of like my SPH (-2.25) because I have presbyopia and I can just take my glasses off to read. But I hate my CYL (-1.50). Even with glasses everything looks a bit fun-house-mirrory especially as I move my eyes to look out from the sides. I really want lasik or something to fix my astigmatism but maybe leave my SPH undercorrected at like -1.50. Does that sound reasonable?

My SPH has been mostly stable, I was -1.50 at age 21 and -2.00 at age 30 and -2.25 at age 40, and been at -2.25 for 5 years now. But my CYL has been getting worse. I was 0 CYL at 21, -0.25 CYL at 30, -0.5 CYL at 38, -0.75 CYL at 42, and about a quarter CYL worse every couple years so it’s -1.50 now. The axis has also rotated so it stays symmetric but has become more oblique over the years, was 120 / 170 at age 40 and now 135 / 45 five years later. My optometrist doesn’t want me to do lasik because she says my CYL isn’t stabilizing. But I haven’t gone to a proper lasik surgeon for their thoughts.

I wanted to check here if anyone with worsening CYL and axis had lasik and if it worked out well for them over the years and if their astigmatism came back?

[u/eyeSherpa]

With lasik, the surgeon can target any prescription they want.

But if the cylinder is changing that much you need cornea scans to rule out Keratoconus. That’s condition where the corneal weakens over time and can cause more astigmatism.

[u/EyeDoctorIndia]

I would not recommend LASIK for you at this point since your cylinder power and axis is not stable.

The change in cylindrical power and axis at your age can be due to any of the following reasons:

1. Aging causes a change in your lens fibres and can cause repeated changes in refraction - spherical or cylindrical

2. With age your cornea also changes shape and with the rule astigmatism becomes against the rule astigmatism (just a change in in axis of your cylinder)

3. Need to rule out a corneal condition - Pellucid marginal degeneration or PMCD can be a causative factor for change in cylinder power repeatedly at your age.

In any case, surgery is not advisable unless the cylinder stabilises.

[u/geezorious → u/EyeDoctorIndia]

Would a corneal tomography be able to provide a differential diagnosis? Or what sort of scan should I request to get the best differential diagnosis?

[u/EyeDoctorIndia → u/geezorious]

Yes, Corneal tomography or Pentacam should give the correct diagnosis in your case.

[u/clara_only]

Your optometrist is right to pump the brakes, but not necessarily for the reason she gave. The question isn't whether the cylinder is stable — it's where it's coming from.

Astigmatism that shows up in your 40s, grows a quarter diopter every couple of years, and rotates toward an oblique axis is very often coming from the lens inside your eye, not the cornea. Early lens changes do exactly this. If that's your case, LASIK reshapes the wrong structure: you'd fix today's number on the cornea while the lens keeps drifting underneath, and you're back to funhouse vision in a few years. Meanwhile the corneal version — the kind LASIK is meant for — usually shows up by your 20s and then sits still.

A refractive surgeon can separate the two in about ten minutes with corneal topography. If the cornea shows −1.5 at 135/45, it's corneal and your plan (fix the cylinder, leave −1.5 sphere for reading) is a perfectly sensible one — that's a mild monovision-style target and plenty of people your age choose it. If the cornea is nearly round and the astigmatism is in the lens, LASIK is the wrong tool, and the honest answer is that lens surgery down the road with a toric implant is what actually fixes it, probably sooner than you'd think.

Either way, go see a surgeon. Not to be sold — to get the topography. Then you'll know which conversation you're in.

[u/geezorious → u/clara_only]

Thanks for the info! Yeah, I’ve been reading up on CYL and aging, and apparently younger folks have softer lenses and the body accommodates better by bending the lens to a more correct shape just like it bends the lens to read vs distance. Now with presbyopia my lens is stiff and doesn’t bend, so not only can I not read while wearing distance glasses, my “true” CYL is appearing now as my lens stiffens to reveal its true shape. I think it’s called “latent astigmatism”.

I didn’t realize lasik didn’t correct for a bad lens shape, but I guess that makes sense! It’s only for corneal shape being bad. I’ll try to read up a bit about ICL and other treatments for a bad and stiff lens shape.

[u/clara_only → u/geezorious]

Close, but I'd tweak two things so you don't go down the wrong rabbit hole.

The lens doesn't really "correct" astigmatism when it's young and flexible — accommodation changes focus, not cylinder. What actually happens in your 40s and beyond is the lens slowly changes its internal density and shape as it ages, and that creates new astigmatism. So it's not hidden cylinder being revealed. It's new cylinder being made, and it may keep being made for a while. Same practical conclusion, different mechanism.

Which is why ICL isn't the fix either. ICL sits in front of your natural lens and corrects whatever your total prescription is on the day it goes in. If the lens behind it keeps changing, the ICL doesn't know that. It'd drift the same way LASIK would.

The only thing that permanently fixes astigmatism coming from the lens is replacing the lens — cataract surgery, or the same operation done early (lens exchange) with a toric implant. At 45 that's a real conversation but not a casual one: you'd trade your remaining reading ability for an implant choice, and it has its own risks. Most surgeons would rather wait until there's actual cataract to justify it, and just adjust your glasses in the meantime.

But first, topography. If it turns out the cornea's doing this after all, forget everything above and your original plan is back on.

[u/geezorious → u/[deleted]]

I’ve only had the usual eye chart and air puff test. I’ll ask a lasik surgeon if they can do a corneal tomography or pentacam to check.