High Astigmatism Low Myopia Differentials?

I recently got my eyes tested and the ophthalmologist said that my glasses were overprescribed.

Previous- Both RE & LE= -2. 25 sph with -1.75cyl in right and -2.25 cyl in left. New glasses - RE = -1. 75 sph with -1.5 cyl and LE = -2sph with -2. 25 cyl.

My eyes are still adjusting to the reduction. And, I bought my first pair of differentials of 0.5 diopters (SPH only) reduced from each eye. Reducing more than that was giving me strain.

I just found out that that I should’ve got rid of astigmatism first🤦‍♂️. Is it going to harm my eyes further if I continue wearing these differentials as I kept the CYL power same for differentials as well as normalized?? Someone please help me out!!

Important note - My mother is not going to buy me another pair for at least 1 year. So, if I can’t wear those diff. I’ll have to use my norm. for all my work.

Your norms and your diffs have the same cylinder correction, so whichever you wear, you will get some hyperopic defocus on your strong meridian with close work. But with your diffs you will get less hyperopic defocus on your strong meridian.
As you have found out yourself, keeping high cylinder correction in diffs, and not tackling cylinder reduction early in your low myopia/high astigmatism situation, were not good ideas.
As you cannot get new diffs, you could wear your norms and push your screen as far as possible for close work, so as not to get your eyes adapted to a different sphere to cylinder ratio in your diffs. How much it would harm your eyes to do close work with your diffs would also depend on how much close work you do. Taking regular breaks for distance vision is essential in either case.

The good news is that you have a reduction in sphere in both eyes, and in cylinder as well in your right eye. This also goes to show how unreliable ‘professional’ measurements can be - who is it that overprescribed you?
One of the things you need to learn to do is accurately measure your eyes yourself. This is difficult with astigmatism, but can be learned. For your left eye, for example you should see the first sign of ghosting/double vision at 24 cm (-4.25D) and the main image should start overall blur at 50cm (-2D). For your right eye it would be 45cm for astigmatic ghosting and 58 cm for overall blur. That is, if your ophthalmo got the measurements right, which is not always guaranteed. You should do this for several subsequent days, and take the average. I do this on printed text in good natural light, as my distance to blur on screen in artificial light is not as good.
I am not in the high astigmatism low myopia situation, and you might get some better feedback from those who are.

So basically, is it going to do more damage if I wear those differentials?

That is only my guess, but my guess is also that the damage will be very small. It may slow down your improvement but is unlikely to do you any physical harm. But do not take my word for it - the decision is entirely up to you.
How do your current diffs work for you? Do you feel comfortable in them?

The important part, and the whole reason for diffs, is to enable you to work at your blur horizon so that you can challenge it with some AF from time to time. If you cannot work at your blur horizon for close vision, either with your diffs or your norms, you need to push the screen further away until you are there.

It’s a pity that you are limited by the number of pairs of glasses your mother is willing to buy for you. Even if you had made a ‘better’ job of your diffs, having to stick with the same diffs and norms for a whole year may slow down your potential rate of improvement. But any rate of improvement is better than none. Good luck.


Dear, I belong to a moderate myopia category with RE- -3.00 SPH, 0.50 CYL and LE- 2.25 SPH, 0.50 CYL, should I drop cylinder in the differentials and normalized? Also, Can we use differentials and normalized simultaneously or on alternate basis ?

You are asking basic questions that shows you clearly need some reading. No spoonfeeding :spoon: here, you’ll have to do your homework! And according to the houserules, we can’t answer diopter specific questions. There are some guidelines but at the end, you’ll have to make your own decisions (may require some trial and error, especially with astigmatism).
This also applies to your other post.

Did you read the 7 days email (see also the start your improvement here post)? You should find some basic ideas in there about how to deal with cylinder in your differentials and normalized.

That said, welcome on the forum :slightly_smiling_face:

Usually it is recommended to use your differentials only (and your full prescription for distance) for a few weeks, after that you can start using your normalized. From there you can use both in the same day.


Yes, I have already read that. Thank you so much for guiding me.

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