Hacker News Reader

Comment by lodovic | Hacker News Reader

I'd be very afraid to fry my eyes. I can't imagine strapping a bright display at 10cm from your eyes, for hours on end, won't lead to eye issues later on in life. I already feel strained after using a headset for an hour.

View on HN

I feel like people had the same worries when television, computers and video games invaded homes everywhere in decades past. I'm thinking the problems (if any) won't be as bad as you think they will be.

And to your last point I think that's where common sense comes in. If something is painful, if it causes you discomfort, stop. You're body is decently good at protecting you from things that are harmful to it (except sugary sweets for me...)

Well specifically to the brightness, how much light is going into your eyes when using a VR set relative to, say, a TV? Or a 27-inch monitor close to your face?

Or the sun/daylight while being outside? I'd guess that's some orders of magnitude more.

Ironically you need to be exposed to the strong light outside (as a child), otherwise you will need glasses.

Yep, I really regret spensing so much time of my youth indoors in front of a monitor... At age 19 I can experience the loss in sight quality already. It is recommended to spend AT LEAST 2 hours everyday outside in daylight to prevent myopia. I did not follow that recommendation and regret it sorely.

The evidence around this appears to be most strong for actually having a long focal distance as being one of the most important factors (as opposed to the lux) - unless the evidence has significantly changed.

I mean there’s probably a pretty strong correlation between being outside and having a long focal distance, but my understanding was that when attempting to control for this (ie rise of increase in apartment living, first in Japan and then other Asian cities) its tightly correlated to not focusing on things a long way away

Yep, that's correct. If you're spending many hours a day in front of a phone or monitor for months or years you'll have accumulated a lot of very short focal length time, so to say.

I’d imagine most discomfort is eye strain rather than brightness. The way VR headsets work right now it’s important to have your eye correctly positioned and the headset adjusted for your own distance between pupils.

You can't really feel pain in your retina though.

The amount of people being prescribed glasses is growing each year due to phone and computer use.

I have poorer vision in low light conditions then when I was younger. My optometrist has confirmed my sensitive eyes and advised to wear blue light filters but I choose not to. I have friends who need glasses to drive legally at night for similar reasons.

Don't give people the wrong impression without first asking professional advice as you could do harm by misleading someone.

While it is true that incidences of myopia are increasing, we don't quite have the evidence to assert that it is due to phone and computer use. Indeed, many studies suggest that the reason might actually be a lack of bright light (i.e. sunlight) and that deliberate exposure to bright light may actually be a good intervention to prevent myopia (see e.g. https://journals.plos.org/plosone/article?id=10.1371/journal..., https://www.nature.com/articles/s41598-018-26635-7, https://iovs.arvojournals.org/article.aspx?articleid=2355431)

Relevant YouTube video about this from SciShow: https://www.youtube.com/watch?v=qwQzTKHIkb4

bright white light or led screens ? ¯\_(ツ)_/¯

From what I remember when I last looked into it: We underestimate how bright sunlight is. Screens just aren't bright enough. They only appear to be bright to us because they are one of the few light sources in indoor environments.

> The amount of people being prescribed glasses is growing each year due to phone and computer use.

I have some hope the use of VR gear might start to reverse that trend. The focal plane is normally set a couple meters away from you -- I think six meters for the Quest. Anecdotally, I find it comfortable to look into; it has a 'night' mode that reddens the light, too.

I don't know how provable it is, but I've always heard that nearsightedness may be caused by looking at things that are too close, too often.

Right now there's a concern in that the focal plane is always six meters, but light-field displays will be coming at some point, probably before these become a mass-market product.

>Don't give people the wrong impression without first asking professional advice as you could do harm by misleading someone.

The irony of posting this after a statement that is patently not supported by any evidence, and is generally thought to be wrong:

>due to phone and computer use.

Word, that sort of claim begs for an associated reference to a study.

I think it's a little bit more then the worries we see with TV's since children under a certain age are not allowed to use it.

But yeah I couldn't imagine using it for a workday. I bought an Oculus Go once, my eyes couldn't handle it for more then 5 tot 10 minutes.

But I guess everyone is different, can imagine for some people like me it's not healthy

The Oculus Go has a resolution of 12.67 pixels per degree. The Quest 2 has a resolution of 15.5 (vertical) to 20 (horizontal) pixels per degree, and a massively reduced screen-door effect.

Anecdotally (i.e. for me), that makes it far less straining to look into. although I'd really want twice that.

While it is physically 10cm from your eyes, there are collimating lenses, resulting in a picture that is apparently much further away from you, I think 1.3m is a typical distance, but it can vary by headset. It is much further away than a typical monitor. As for the light itself, it is light, no UV, not overly bright, sunlight is orders of magnitude brighter (which is a problem for AR btw). The image is also in front of you so no weird eye movement. I don't really see how it can damage your eyes though maybe some people know better, maybe the low resolution/screendoor effect can be a problem on current-gen headsets.

There are things that can cause strain. For example, items too close to you can be out of focus, the low FOV makes you move your head a lot more, and it has extra weight strapped to it, there is the heat, the motion, etc... But a well designed desktop setting like in the article avoids many of these problems.

One nice thing is that (next to being able to dim the screen as there is no background), the eyes actually focus on infinity with the lenses in a VR headset. This is the eye's natural state (staring in the distance, relaxed circular muscles around the lenses, which then flatten), and should be much better in the long term that staring at a screen 50 cm away from you.

Generation 1 headsets were focused at infinity, these days they're focused around 2 meters[1].

[1] https://twitter.com/ID_AA_Carmack/status/1130973138362294272

Ah, thanx for the the clarification! Would be neat if it could be set at a therapeutically optimum setting or something. Or perhaps vary? Or that would be weird I guess. Best thing would be if certain elements require close focus, while others require one to focus on infinity. In a ratio that mimics natural use. But I guess that is a lot more difficult to implement.

Btw, too little light is also not good for the eye, outside, in the sun it can easily be 100x brighter than your screen and your eye needs that every now and then to remain in good shape.

I am unsure wether you are aware that the screen is only physically 5cm away. But our eyes have to focus (Focal Distance) on a distance of 2m (oculus quest 2) or infinity (vive) (afaik, i'd love to get more detailed informations on what glasses have what focal distance). This is archived by the fresnel lenses used in the vr glasses.

So it's not the problem focussing something in 5cm distance. The big issue is that your eyes never have to adapt the distance they are looking at. Watching a screen all day 50cm from your eyes is equally bad. You could say that focussing a distance 2m or infinity is better, but i am no eye-scientist.

People keep bringing up vision problems, but I think my biggest concern would be circadian rhythm. How does my brain know when to release sleepy chemicals when I shut off the daylight for 10 hours at a time? All that artificial light would really mess up my sleep patterns. Although, with the winters we have here, it wouldn't make a difference during the twilight months.

I imagine that's something that could be compensated for within the virtual environment -- similarly to the way apps like f.lux change the average colour temperature of a screen depending on time of day.

I've had problems with eye pain for years due to, what I thought, was computer use.

After a lot of trial and error and just thinking about what could possibly be causing this, I believe I have found that I wasn't getting enough sleep. I haven't had eye pain in months and I have been using my computer even more frequently than before (because my eyes don't hurt).

I have learned that I need at least 8 hours of sleep, but try for 8 1/2 - 9 hours. If I go a couple of days getting 5-6 hours of sleep, my eyes start killing me again.

Might be worth looking into your sleeping habits.

There’s no headset display on earth that will be brighter than the outside world on a sunny day, and we’ve evolved to handle that for 8+ hours a day indefinitely.

Likewise. I worked from a laptop for the last decade. Got a new job and switched to a large monitor that I sat pretty close to. 6 months later I needed glasses after having perfect vision for 30 years. It could be coincidence but I feel the screen caused the vision deterioration. Having a screen strapped to my head sounds like it would be a more extreme version of the large monitor.

Using my phone is frying my eyes today. I am getting lots of eyestrain and blur from too much phone time. Once I got a Quest 2, I substituted enough screen time that my eye strain issues went away. Not saying there will be no long term effects, just that today in the here and now, my eyes feel better using VR for an hour or 2 a day.

I’m sure that I would fry my eyes. When I was working with 6 screens for one year and half I couldn’t focus anymore far away, everything was blurry. After years that I didn’t use that setup now my eyesight is normal again. I can’t imagine what would do to my eyes to focus on a screen mere centimetres from my eyes.

Indirect sun light on average sunny day is many times more energetic rhan anything screens put out.

Is the output of the sun somehow equal to the output of LED lights? One could imagine there are slight differences in how they react with the eye, so they probably bring different issues by being received by your eyes for long durations.

Not to mention humans have evolved with sunlight in mind and LED lights are relatively new. Our eyes most likely are more used to sunlight than LED lights.

I would feel the same.

I'm not ophthalmologist but I do wear glasses for myopia. My concern would be emitted light, distance and emitted heat...

Screens are emitted light. Having a screen strapped to your head emitting light into your eyes is very different to having a monitor in a room (adjusted to ambient light) emitting light and in an environment with a lot of natural reflected light.

Distance, yes there are lenses that bend the emitted light and change the perception of distance to the screen but it's still only a short distance from your face emitting light and heat.

You might be fine for a few years but I would be willing to bet you will have some form of eye issue in later life.

Isn't everything picked up by your eyes emitted light?

No.

Think of it like a cinema projection vs TV screen.

In a cinema a projector sends light onto a screen that bounces off and towards your eyes, this is a reflected light.

If you were to watch a TV of the same size it would be emitting light from LED's shining light directly to you.

There are some comments on an older thread with some good info: https://news.ycombinator.com/item?id=17993615

Direct or reflected light is just light. Same stuff.

What matters is the content and quality of the light spectrum.

LED lights or even LCD screens can be designed with a more or less healthy spectrum depending on the priorities of the manufacturer. But this is an economical problem that can be regulated.

As many people pointed out, the focal point is at a much higher distance than the typical screen.

If anything, this could be much healthier.

If only the head mounted displays were designed with health in mind rather than making a quick profit...

Reply on news.ycombinator.com