TL;DR: VR is possible after cataract surgery.
Eighteen months ago I had eye surgery for a form of early-onset cataract which was seriously affecting my vision, and for which the treatment is the same as for the more usual kind, ie removal of the natural intraocular lenses and their replacement with artificial ones. In this thread I undertook to report my experience of using the 8KX when it arrived.
This is a complex and evolving subject, but for the purposes of this discussion, the main point about artificial intraocular lenses (IOLs) is that they do not physically deform like natural ones, and hence one loses the ability to change focus. This represents a potential problem for VR. There are some “multifocal” IOLs which focus at various distances at different points on their surfaces, and mimic variable focusing by relying on brain plasticity to sort out the confusion. Because my main interest is high-end manual focus photography, including on-screen pixel-level editing, my eye surgeon recommended against these, as the sharpness is degraded compared to fixed-focus IOLs.
So I ended up with IOLs set to different distances - about 1.5 metres in my left eye and about 10 metres in my right (and dominant) eye (part of the deal is that the IOLs also correct any existing astigmatism). The magic of brain plasticity means that this gives me the impression of continuous sharpness from about one metre to infinity. The brain takes the sharpness from whichever eye is sharper at the distance you are looking at, and combines that with the spatial information from both eyes to give stereo perception. I am not conscious of where one eye takes over from the other as I look at different distances. I need prescription glasses (a simple +1.5 diopter) for reading and phone use. Because I can’t be bothered constantly taking glasses on and off, I wear bifocals with clear glass on top and +1.5 below.
For extended or critical screen work I got a separate prescription which sets both eyes to sharpness at about one metre. I asked my eye surgeon about these and her strong advice was not to get them until about six months after the surgery, to allow the necessary neural rewiring to occur. In the event I waited almost a year, and don’t wear them for more than a few hours a day.
If it helps to understand, with my unaided “pseudo” depth of focus, I cannot resolve those pictures where you look at apparently random dots and they resolve into a 3D dinosaur, because for that you need sharpness in both eyes. But with the prescription that sets both eyes to the same distance, I can.
When my 8KX arrived, I found that my left eye (approximately 1.5 metre focus) was pretty sharp, but my right was not so good. I tried using the one-metre glasses, but (a) this was focusing a bit too close, and (b) I realised that the glasses were rubbing against the 8KX lenses and damaging both, so I stopped using them. My original plan had been to get glasses set to around 1.5 metres to use with the 8KX, but the risk of damage now ruled that out.
While using no glasses at all with the 8KX was almost acceptable, it wasn’t great. So I decided to go with prescription inserts from VRMust. COVID restrictions where I live mean that a visit to an optometrist wasn’t an option for the time being, so I went for a slightly more empirical approach. Knowing that my left eye was pretty good with the 8KX, I went to my local pharmacy and tried various cheap reading glasses, establishing that a +1 diopter would set my right eye to about the same focal distance as my left. I then ordered inserts from VRMust with zero magnification in the left eye and +1 in the right. As my previously significant astigmatism was corrected by the IOLs, I did not need to specify any other corrections. Since my 8KX arrived with only the thin foam, I ordered VRMust’s padded foam as well.
Apart from the online tracking from their delivery service, which is rubbish, I have no complaints at all about VRMust. They filled the order and dispatched it very quickly, and it got from Shanghai to Melbourne in not much over two weeks. The inserts do not come with instructions, but it was not too hard to work out what to do.
The result was that, with the HMD on, both eyes are pretty clear in their respective sweet spots. I have the same issues as many others that the 8KX sweet spot is tiny, and the right lens cannot be moved in far enough. And finding good IPD settings, physical and software, takes ages and seems to have no relationship to one’s actual IPD. If someone could manufacture decent lens replacements, I would seriously consider them.
In conclusion, if you have had or are contemplating cataract surgery, you should still be able to use VR. I would counsel, however, that the choice of the type of artificial intraocular lens might be important, and that it might be necessary to limit or avoid VR use for a few months after the surgery.