Is it a good idea to equalize when the diopters of both eyes are different for about 0.5 based on the cm measurements?
According to the powers that be (@jakey), a difference of 0.50 diopters between both eyes is within the range of ocular dominance, so you shouldn’t need to equalise the difference.
Whether your cm measurements were completel accurate in telling you that there is a gap between your eyes of 0.50 is another question, hopefully they were
It is recommended to equalise your eyes latest when you are around -1.5D with your normalised glasses. The simple reason for it is that at that point you no longer need glasses close-up so you will have equalised no-correction close up. And it is easier for the brain to switch from not corrected close up to distance if your normalised is equal, too.
I’d say the general formula recommended by most would be as follows
- (if you are still well above -2D, just do equal reductions from both eyes - unless you definitely want to start - still, do not skip the next point)
- reduce 0.25 from both eyes a few times (both differentials and normalised) - to get used to the process and get to know your eyes better (e.g. -3.0&-2.5 to -2.75&-2.25 to -2.50&-2.0)
- when you decide to equalise, do it with 0.25 reduction (e.g. -2.25&-2.0) - this will most probably take 2 or 3 times longer than the equal reductions did, simply because your brain will have to work harder on the image processing, too
- then a few more 0.25 reductions from both eyes (e.g. -2&-1.75 to -1.75&-1.5)
- when you feel ready, equalise again (e.g. -1.5&-1.5)
Though people drop differentials below -2 typically, if your eyes are not equal, you may keep very weak differentials for a bit longer and do the equalising with those, too.
Would you recommend plus lenses for close-up if you are in the -1 range for the myopic eye but your other eye has 20/20 vision?
(This is my situation and my right eye was initially at -1.75 but this was mostly over-prescription and ciliary spasm. Left eye doesn’t need correction at all).
I won’t. Anyway please don’t go out of topic, could you?
The question sounds like hijacking the topic at the first reading, indeed. But I think it was raised here due to @dharini215’s special case. I suggested going with a few equal spherical reductions first before equalising and for Dharini that would mean plus lenses for the non myopic eye. And to answer that: no, I would not recommend plus lenses. In that case, there is no other way but jump into equalising immediately in my opinion.
On the equalising part. What I found is that it’s key to understand if the eye with the higher diopter is actually behind, or the eye with the lower diopter is gaining a lot more from AF rushing ahead. Can’t comment on big differences from personal experience, I’m afraid. The gap between my eyes was 0.25D in correction, almost moving towards 0.5D (meaning was already around 0.375D difference), now it is less than 0.12D (so counts as 0.0D). And it was a mixture of a bit of patching to improve the eye to catch up, and a lot of “switching off AF” in the better performing eye to let the eyes improve together.
It is interesting you said I should use plus lenses for the non-myopic eye- I was thinking
that using plus lenses only for the myopic eye for close-up would help with equalizing.
Would distance patching be more appropriate if you are trying to equalize and you have low myopia?
I have low myopia and difference in the 0.25-0.5 D range (L is weaker). I equalized when I first started and now I think that may have been a mistake. I’ve been feeling chronic tension and pain in my left eye. I think it’s because it has to work harder than the right, especially with computer work. For distance vision it may not matter so much.
I’m sure ocular dominance is natural, but then again our eyes never evolved to handle so much close-up and precision work. At least in my case, my eyes seem to be sensitive even to a 0.25 difference in close-up. I’ve gone back to an old pair from before equalizing and I can feel the left eye relaxing. I need to reevaluate what to do going forward.
Bianca has a good view on equalising.
0.25-0.5 is a ‘natural’ range of equalising.
Therefore she doesn’t stress if she needs to go up and down within a range of 0.25.
Have a look how she goes up and down throughout her progress.