@Aparna, if it were me, I’d just go by the old cyl correction and new sphere correction when ordering, because I’m used to that amount of cyl already. That way, you’re only changing one thing at a time (sphere). Then 4 months or so down the road when I needed another new pair of glasses, I’d work on reducing the cyl. But that’s just me…you might decide to take a different approach. But since you have the new rx from the exam, you know your sphere needs a reduction, so really there’s not much of a choice.
But yeah, I’d have the exact same concern that you brought up about changing too many things at once (and would be afraid to change the cyl right now because of that).
When you do eventually reduce the cyl, it’s probably wise to keep the spherical equivalent as you said. (The formula is: 0.5 cyl = 0.25 sphere in terms of power.) Make sure you keep the sign (plus or minus) as well. In other words, you add half the cyl to the sphere to get the spherical equivalent. But that will probably come later on for you, rather than right now since you’re working on sphere right now.
I wouldn’t increase the right eye sphere unless I really needed to. If you can avoid increasing the diopter difference, don’t. Since your new rx is very recent, you can probably avoid having to do that.
Again, I would keep the diopter difference and the cyl the same as with what you’re currently wearing, and only change the sphere. That is what Jake recommends.
I also forgot…how long have you been using differentials already?
Good luck, and let us know what you end up doing for normalized.