Eyestrain discussion / Problems and Solutions



Things are more complicated then that :
1-the current head strap is crap, I would be the guy telling you pimax headsets are blurry if I was not using my own head strap.

2- the first thing pimax must do is assert the problem in a controled environment with numerous people selected with racial and gender variations in mind.

3- Pimax could redesign the lens and simply have another 20% of people not been confortable with the new design. This is why big cie will avoid wide FOV headsets in main stream market because the optical system become to critical and it’s difficult to achieving the normal sigma value for those kind of commercials products

4- having a one design fit all may even not be possible…


By curved I meant slightly shell shaped lenses and curved lines being longer once straightened out. My argument is summarised asking: how does diverging or cantering the screens; which creates a closer together sweet spot due to divergence compared to flat-planed vr lenses; equate to a higher physical IPD measurement on a divergent vr display?

What I mean by that is if you take a normal VR headset, and assuming every other flat planed VR headset has a consistent measurement between the actual measured distances between the middle of the lenses and the on screen IPD readings;

And assuming Pimax takes into account the divergence of the screens when calculating and displaying on screen IPD measurements;

How do we get a smaller physical reading on screen at minimum IPD (59.9) when the actual physical minimum distance of both lenses are 70mm.

Cantering displays should bring the middle of the sweet spots slightly more together compared to a flat-planed panel setup with the same lenses, in a similar way to how adjusting down the IPD measurement brings the pupils closer together, although this is achieved by reducing the angles. The middle of the line of a 45 degree angle would be closer to the originating point of the axis compared to the middle of a 90 degree angle.

You would think that considering all flat planed VR headsets besides Pimax have consistent measurements between the actual far IPD of a user and the on screen IPD reading, that Pimax would have to increase the on screen IPD reading to compensate for the reduced angle from the divergent displays, so that your personal IPD measurement could accurately be translated to flat plane VR where the on screen IPD is the same as actual IPD measurements.

Conversely, with Pimax headsets you have a reduced on screen IPD reading and a larger physical minimum gap between the middle of the sweet spots of both lenses.
Due to divergence of the screens, one should expect a lesser physical minimum measurement between the middle of both lenses compared to flat planed VR headsets and a greater on screen IPD measurement to account for that divergence.

Why is it then that the minimum physical distance between the middle of both lenses is 70mm? And why is the physical minimum measurement more than the on screen reading minimum of 59.9mm?
It should in fact be a lesser minimum IPD measurement due to the divergence of the screens making the middle of the sweet spots closer together compared to normal flat planed VR lenses.

Additionally the manual advertises 55mm minimum IPD to use the devices, and the on screen display is 59.9mm. This is clearly false advertising on behalf of Pimax on two fronts (lying manual and lying on screen IPD) and is a massive issue to those who backed or bought the headsets under the premise they could use the headsets, when in fact they could not due to experiencing heavy eye strain or being unable to get a clear image in both eyes due to a lying IPD measurements on screen and the fact the lenses minimum distance is 70mm, not 59.9mm like it says on screen is the minimum, 55mm as it says in the manual as the minimum, or even 65mm which users should not have a problem with. (If it was in fact 60mm IPD).

Many of those customers and backers have found that they are simply unable to use the new Pimax headsets comfortably or for a significant amount of time, due to the abovementioned issues. To the point where a significant and memorable amount of those customers and backers have reported on these forums that they have had to sell their headsets because they cannot use them at all, even after having tried the extensive amount of fitting suggestions to eliminate these problems; such as trying different sized facial foam thicknesses, moving the headset further away or closer to your face, altering the placement of the headset up and down on your face or altering the upwards or downwards tilt of the headset. For some users in the 60-65mm IPD range these advices simply do not work to correct issue such as providing clarity in both eyes.

There is no way of understating that this is in fact a massive issue and it is occurring for a significant amount of users, such as @RiftFlyer @bosnaboi and @nikkic to name a few beyond the unanimous assessment of these issues by 6 reviewers referred to in the OP in this thread and all the other reviewers and backers experiencing these issues on these forums and on the sub reddit.

My assessment is the minimum IPD possible to use Pimax is around 64-65mm IPD (at 59.9mm on screen IPD reading), but that puts your pupils at the edges of the sweet spots of both lenses.

Tell me about one VR lens design that isnt made to be looked at in the middle, or that the sweet spot isnt in the middle and I’ll concede I’m wrong. As far as I can tell this error was may have been made with lack of foresight to IPD in efforts to maximise screen real estate.

I propose that the IPD issues of discrepancy and being unable to get a clear image in both eyes, and eyestrain issues could be solved by shaving off 5mm off the inner parts of each lenses towards the nose and creating a rubber adapter for the smaller 160/190 fov lenses, which sits at the outer distorted part of the lenses, which will allow for compression of the adapter when IPD is adjusted outwards to the maximum value and an accurate on screen reading in comparison to real IPD measurements.

@Sean.Huang @PimaxUSA @Dallas.Hao @mozi An official response would be appreciated as to whether or not my abovementioned suggestion for a smaller lens design will be considered and implemented as a purchasing option and a replacement lens on store, as a smaller lens of -5mm off the inner side towards the nose and an outer periphary rubber compressible adapter would entirely solve the three problems.

    1. IPD measurement discrepancy issues
    1. Eye strain related issues.
    1. Customers within the 60-65mm IPD range being unable to get clarity in both eyes at the same time.

A picture speaks a thousand words, so I’ll attach two. Pimax please solve this issue. Also second pic for everyone ITT arguing against this issue.



Xunshu - Wide FoV headsets have there compromises.


Wide fov headsets having compromises has nothing to do with misrepresenting IPD information on screen and in the manual, that IPD discrepancy likely happened due to wanting to maximise screen real estate.
I provided a solution, its to reduce each inner lens by -5mm and make a compressible rubber adapter for the outer peripheral edge, so that the lenses sit in the same sockets without modification.


Well we know this lens is final. So we will have to see what can be done with software. The biggest problem in truth we donot understand this custom lens design.

High FoV headsets have there compromises.


We also have to bear in mind most of @PimaxUSA’s test subjects were only exposed to the 5k and 8k experience for a short amount if time, in 2-5 minute sessions.

This is simply not enough time for issues such as eye strain to appear.

Alternatively, we have a review by 6 backers who tested each others headsets for extensive periods of time who reached a unanimous assessment that the devices cause eye strain and cannot be used for extensive periods of time (I hypothesize they are within the 60-65mm IPD range and that’s why), as well as all the users on reddit and the forums saying this is an issue and identifying the same problems.

Compromises or not, that has nothing to do with the IPD measurement discrepancy which appears on screen and in the manual where minimum usable IPD values are indicated. That’s false representation and false advertising how I see it.

What if I had 55mm IPD or 60mm IPD and I bought Pimax under the pretense I could use it?

I just can’t? I’d be SOL? That’s a sad set of circumstances and reality for a lot of backers and customers which they’ve had to deal with, and it’s a reality which is being ignored by Pimax and discredited by naysayers, when there’s plenty of people saying these same issues have caused them to sell their headsets due to being unable to use them comfortably at all, after following all extensive fitting suggestions.


Yeah I remember many selling the Vive after launch due to sde causing eye strain & nausea. Good thing as @TrevorVR said folks adapted.


Who says it is misrepresenting? It is simply varied by factors. One is being explored in terms of manufacturing.

The simple truth your trying to apply your understsnding from simple VR headset that anyone can make with one that is completely different.

“It’s not what we don’t know. It’s what we know for sure that just ain’t so.” Varistion of Al Gore’s statement.


These ppl are of thr same region & as such is not good enough sampling.


On all other VR headsets the measurement between the middle of the lenses is consistent with IPD readings.

70mm minimum lens distance =/= 60mm minimum IPD as the sceeen says, nor does it equal 55mm minimum IPD as the manual advertises as a specification.

That is clearly false advertising in the manual, and a misrepresentation and inconsistency between the on-screen IPD reading and the minimum physical measurement between lenses.

My above lengthier post 8 replies earlier clarifies that clearly, and how every other explanation to account for the IPD measurement discrepancy is impossible and not consistent with what’s observed.


You have measured StarVR headsets? Thst is the only one that uses special custom Hybrid fresnel lenses. Stop comparing apples with oranges.

StarVR is the only headset that can directly compare as a result.

So not going to bother further as your stuck.


Regardless of StarVR, it’s irrelevant to the fact a divergent display should reduce the minimal distance between the lenses compared to
flat-plane vr lenses to allow for smaller IPD.
And if the on screen IPD reading and physical minimum measurement between both lenses are accounted for and different due to the diverging displays as Pimax says;

Then an on screen IPD reading should be greater than the actual distance between the middle of both lenses, not less than by 10mm, if it were simulating a normal far IPD which is directly translateable into the distance between both lenses in flat planed vr headsets.

This is not what Pimax has, conversely we have the opposite.


Call me when you have studied other cantered headsets with custom optics. Until then your argument has very little meat.


You can’t even compare other lens designs when most wide-fov cantered vr headsets on the market have been using fused lenses and up to 4 displays.

I’m well aware, clearly something doesn’t make sense to you about the fact the middle point of a line on a 45 degree angle is shorter than the middle point of a line on a 180 degree angle.

So why don’t we have a greater on screen IPD reading to account for real IPD measurements? We have a lesser one. It doesn’t add up by logic any other way besides the lenses are 10mm bigger than the software measurement given on screen.


I would like to share my practical feelings of IPD, Overlap, and Sweetspot from my 5k +. This is not meant scientifically. I have an IPD between 65 and 65.5 and need on the cheekbones a thickening of the foam of 5-10 mm. On the headset, my IPD is set to 65. I use “Heliosurge’s” photo as startup screen.

When I now open and close my eyes one after another, I see the overlapping of the lenses. I also see the black fabric between the lenses. For me, I clearly see the entire overlap and it’s my sweetspot. That’s almost the full size of my old Vive. I’m so impressed. I can feel the overlap on the outer edges, but if I focus my gaze in the middle on the distance, the overlap is forgotten. In real life, they also forget their nose as a disruptive factor. The nose is skin color, if now the black material between the lenses would be skin colors, we would forget also here that there is an overlap. I will test that. Although I still have little graphics power but little-claimed games are terrific for me. What annoys me the most is that I can not exhaust the resolution of the 5k +.


I didn’t know Panasonic represented most.


The startup pic is not of my creation. Another member made it.


Ok, but they shared it here in the forum :sunglasses:


You forgot the early versions of VR Hero and Palmer’s prototype with fused lenses.
My underlying point when I mentioned fused lenses is each wide fov and cantered vr design is different, there is no standard cantered lens design yet and always room for improvement; do you want to address my question instead of going on a tangential and arbitrary note?


None of those exist anymore and Palmer at last post was quite happy with his pimaxes. Hero now xtal uses the same cantered display model & customized lenses.

Leaving Panasonic only one left using fused displays & optics(which has problems of it’s own)

So again come back when you have studied other Wide FoV headsets with Cantered displays & custom optics. As you also have to add in rendering for these designs.

Pics of starvr lenses uses a similar lens design & version 1 had fixed lenses.