So I’m on my 2nd pair of normalized, with my next SPH reduction my SPH is going to be the exact same number as my CYL in the same eye, and my question is if that’s good or bad or nothing to worry about? I have read the blog on astigmatism, and watched Gems videos but I haven’t seen anyone mention this, because everyone I know that has both SPH and CYL the numbers are never the same in the same eye, either one is higher or lower but never the same in the same eye. So what I’m thinking of doing is I reduce just the CYL in my next normalized and don’t touch the SPH since I know you’re not supposed to reduce both at the same time.
When you say SHP, you mean SPH (short for sphere = spherical because the lens has the same power in all directions)?
SPH needs show your general level of myopia and CYL additional power needed in a particular direction, so they are independent of each other. If your overall SPH is reduced you’re reducing the lens power in all directions including the direction in which your CYL gives you extra refractive power, so you see it’s not really relevant whether they’re the same number or not.
What’s true is that usually CYL is lower than SPH because it’s like the tweaking number on the general myopia number.
So if I have -2.00 myopia and -2.00 astigmatism in my left eye it’s ok?
I don’t see anything wrong with it. As long as you can see with them I think they are fine. I too have a similar situation (distance glasses had sph to cyl ratio of -3.25/-3.25). You might eventually end up with no SPH but still have some CYL left over and that’s okay. Some people in the endmyopia community have been prescribed 0 SPH and only CYL correction. You might want to look into spherical equivalent (reducing CYL but adding more SPH to compensate) but this might be harder to get adjusted to, so “listen” to what your eyes are asking for.
It’s possible, sure.
Since you had 2 drops from sph already you know what a “drop and then the working for clear vision” is. EM recommends dropping from sph first to get into the practice, learn about your eyes and have some positive experience before working on more complex changes like cyl or equalising.
So it would be sensible to try a cyl drop next. Cyl drop usually takes more time and patience as the brain’s adjustment part is more significant. And yes, it is not recommended to reduce from sph and cyl at the same time as if you later find it a challenge to clear the blur you won’t know which part was too much.
Basically you have 3 options: drop small from the cyl, drop more from the cyl, drop more but add some sph back. Since you are used to the cyl correction within the eye and because the cyl value is relatively high, I wouldn’t recommend going cold turkey on cyl.
I assume you still wear differentials for close up. Most people find it helpful to drop cyl from both diffs and norms. Most people keep it consistent, but some people can drop a bit more from diffs than from norms, or only drop from diffs first.
You can try determining the drop by measurement or by making a decision and testing the result. There’s no right or wrong way. Most probably there will be a bit of stepping back and forth during the journey of reducing cyl, the brain can be a stubborn part…
Brace yourself for more ghosting challenges while the brain is trying to figure out how to process the different amount of blur within the image coming from within one eye plus then merging the left and right images… But when you crack the code, you’ll have one more EM skill under your belt!