High astigmatism with positive sphere

Hey everyone!

I’ve been doing endmyopia for two years now and I told a friend of mine and she wants to try it. Only her prescription is minus cylinder but positive sphere:

L +0.50 -2.25
R +0.75 -2.25

I am a bit in doubt as to where to start. Definitely leave the plus sphere in there in the beginning, but I am confused as to how to use the spherical equivalent methode. Because she does not have minus sphere, but plus sphere, so I cannot substituten cyl for sphere??. Anyone here who can point my in a direction as to what to read to figure out what steps to take?

I thoughts first reduce astigmatism for close up, then for normalized, but I am not sure how to change it, since she had the plus sphere.

Any tips of pointers to info post would be really appreciated! :slightly_smiling_face:


Can’t give you diopter specific advice. You’re going to have to do the work here.

Take that cylinder.
Compute the equivalent sphere.
Keep your signs straight!
Now “Add”, keeping your signs straight, the plus and the minus.
Your friend is myopic, not hyperopic. The math now says by how much.

Complex prescription
Reducing prescription complexity
Astigmatism - Complex Prescription

1 Like

You might also be wary of giving your friend diopter specific advice if that’s a licensed profession where you are.

Thanks you! Yes I am NOT asking diopter specifics, Just pointers to what to read to figure it out. So thank you for the links, we will get into it!

If I understand correctly , by computing the equivalent, I will be changing the sphere from plus to minus, by “adding” the equivalent minus sphere. (If that is alsof specific advice, sorry, ignore it )

1 Like

Ow I am a bit slow, I think I get it. By wearing plus sphere she is sort of doing “plus lens therapy”, but in fact she is myopic? No not sure this is correct.

No, the plus is only compensating for the minus. The net correction is still minus.

1 Like

Do you mean the plus is compensating for the minus CYLINDER correction, that by having so much cylinder correction she has that plus correction to compensate for it? So if you calculate the equivalent sphere, the plus will turn into minus sphere (and the cylinder will be lowered). And then the netto sphere is minus?

I really appreciate your answers by the way :slightly_smiling_face:

Basically, you’re combining that minus equivalent with the plus. The plus cancels out some of the minus, and leaves a little minus left.

Exactly, that is how I understood it. The only thing that confuses me with this, is that by doing that you take out almost all the cylinder at once and substitute it for the equivalent sphere. But is it not really confusing for the brain to take out so much astigmatism at once? (By going from +0 .75 -2.25 to -0.25 -0.25)

It’s a thought/math experiment, it would be traumatic to actually do that all in one step with the lenses. I’m not at all suggesting you do that with the lenses. I’m suggesting you understand the lenses she’s wearing before you try to “fix” her “hyperopia” that she doesn’t have.

Thanks, you’re right about that.

So the sphere substitution math does work the same way, you’re substituting half negative sphere for cylinder, but when you add negative numbers to positive numbers, you’re canceling out, so you’ll drift towards 0.

Yes exactly! But if you were to do this for real, small steps would be best I suspect. Because she is still adapted to the plus sphere and the cylinder. And she cannot really do bifocal spherical reductions in between. Since she has plus sphere

Jakey is convinced there’s something special about crossing over 0, but mathematically you do have room to go a bit more plus. Thing is though, you’ll probably want to drop only a quarter diopter of sphere at a time, you probably won’t be doing all those spherical equivalent corrections, just some of them.

1 Like

What do you mean by only some of them instead of all? Because she cannot do any of them right, because she does not have negatieve sphere. Or do you mean she would be doing spherical bifocal reductions by going a bit further info the plus (and she can’t go to far, so she can’t do all of them?)

My Idea would be that she starts with a normalized slightly lowered in cylinder with the equivalent negative sphere added. And a differential that corresponds to that. And she hoe that goes.

Ah I get it. If she does alle the bifocal sphereical reductions by going further in the plus, she Will end up with only plus left and no astigmatism anymore. But then she has the plus left soo that is not Ideal??

So, a spherical reduction for a myope is more plus power, a spherical equivalent for minus cylinder is more minus power.

Some sample drop sequences:

Standard sequence (Less complex situation.)
Sphere Cylinder Spherical Equivalent Note
-5 -3 -6.5 Starting
-4.75 -3 -6.25 Spherical Improvement
-4.5 -3 -6 Spherical Improvement
-4.5 -2.5 -5.75 Cylinder drop
-4.25 -2.5 -5.5 Spherical Improvement
-4.25 -2 -5.25 Cylinder drop
-4 -2 -5 Spherical Improvement
-4 -1.5 -4.75 Cylinder drop
-3.75 -1.5 -4.5 Spherical Improvement
Standard sequence (Low myope, High Astigmatism, does not work)
Sphere Cylinder Spherical Equivalent Note
1 -3 -0.5 Starting
1.25 -3 -0.25 Spherical Improvement
1.5 -3 0 Spherical Improvement
1.5 -2.5 0.25 Cylinder drop
1.75 -2.5 0.5 Spherical Improvement
1.75 -2 0.75 Cylinder drop
2 -2 1 Spherical Improvement
2 -1.5 1.25 Cylinder drop
2.25 -1.5 1.5 Spherical Improvement
Exchange Cylinder for Sphere (You run out of sphere to exchange)
Sphere Cylinder Spherical Equivalent Note
1 -3 -0.5 Starting
0.75 -2.5 -0.5 Exchanging Cylinder for sphere
0.5 -2 -0.5 Exchanging Cylinder for sphere
0.25 -1.5 -0.5 Exchanging Cylinder for sphere
0 -1 -0.5 Exchanging Cylinder for sphere
-0.25 -0.5 -0.5 Exchanging Cylinder for sphere
0 -0.5 -0.25 Spherical Improvement
-0.25 0 -0.25 Exchanging Cylinder for sphere
0 0 0 Spherical Improvement
Mixed Cylinder Reduction types
Sphere Cylinder Spherical Equivalent Note
1 -3 -0.5 Starting
1 -2.5 -0.25 Cylinder drop
0.75 -2 -0.25 Exchanging Cylinder for sphere
0.75 -1.5 0 Cylinder drop
0.5 -1 0 Exchanging Cylinder for sphere
0.25 -0.5 0 Exchanging Cylinder for sphere
0 0 0 Exchanging Cylinder for sphere

But you don’t even know if she will tolerate smaller straight drop or a cylinder exchange better. Planning a sequence in advance only goes so far.

1 Like

Yes you’re right. Planning ahead does not really work here. Better to take it one small step at a time and see how far that Will Go Thank you for all the information!

1 Like

@Eve Did your friend ever make progress?

I agree with this sentiment.

L +0.50 -2.25
R +0.75 -2.25
There’s 2 working definitions of hyperopia. One is farsightedness, + lens user. The other is “weak accomodative muscles” which gives this wide range from strongest axis being “-2.25” and “weakest” axis being +.75. So even though the spherical equivalent here indicates that the glasses is myopic. The nature of this prescription indicates that the doctor wanted to give the person a prescription from +.75 to -2.25. She’s a near-sighted hyperopic. And the spherical equivalent would be -2.25/2 + .75 = -.375

So, generally our advice for myopic people is to relax. Oppositely,

For someone with this type of hyperopia. As long as there isn’t something fundamentally wrong with their muscles, they can also reduce their prescription .25 at a time. Astigmatism exercises are valuable (see jake’s latest podcast w/ Andie.) And, most importantly is for them to focus on detail. Honing into how things look to work on their focusing muscles. And at some point as you increasingly decrease the gap this person will go from being hyperopic, to being myopic with low -SPH and comparatively high -CYL

So like for the R eye,
+.75 -2.25
+.5 -2.25
+.5 -2
+.25 -2
+.25 -1.75
0 -1.75 (note, Some places don’t give 0 SPH)
0 -1.5
-.25 -1.5
-.25 -1.25

There’s some therapy for this type of stuff that could quickly speed up the gains at a much faster rate than .25 at a time but finding a worthwhile and not too expensive place is difficult.

Alternatively though, the person can just focus on reducing their astigmatism per reduction. This path should have the least amount of overall reductions needed to 0. But the previous path has the least amount of overall reductions in reducing the gap between SPH and CYL. Not sure which path is better, since we don’t get a lot of hyperopic people. My gut instinct is that the below path is better than the above path.

+.75 -2.25
+.75 -2
+.75 -1.75
… Until the SPH equivalent is 0
+.75 -1.5
And at this point the person can continue reducing .25 at a time, alternating between CYL and SPH or some other method of your choosing. They can possibly even go bare at this point but a 2.25 diopter gap is still huge

1 Like

Wow, thanks for the detailed response!!
My friend did never start with reducing though. She does believe the concept, but does not really want to put in the effort. I guess she does not really care that much about it, like the other few people I told about EndMyopia… It’s a shame though :confused:

1 Like