Is it dangerous to look at the red light in the headphone jack?

Question

I recently purchased an early 2009 model white MacBook. Today I was installing Windows on it and I noticed a red light coming out of the headphone jack. I thought there must be an LED in there to help you locate it in the dark. I was curious about it so I crouched down next to the computer and looked inside the jack to see what the deal was.
At the time I didn't know that there is such a thing as an optical audio jack. Obviously I now know that's what the red light was all about. Now I'm wondering if looking at that light could have injured my eyes. Is it a laser, an LED, or something else? Does anyone know how dangerous it is to look at that light? I looked directly at it from close range for perhaps 3-10 seconds, with eyeglasses on. I don't remember it seeming uncomfortable to look at.

Answer 1

Thank you both for your replies.
GfulDedFan wrote:
To the best of my knowledge, that light shouldn't be on when the port is empty.
Yes, my understanding is that that light should only ever come on when there is a Toslink mini-plug adapter inserted into it (or at least a regular 3.5mm analog plug). However, like you said, I've seen a number of posts on the internet about that switch that turns on the digital output (red light) getting stuck in the on position (even without having plugged in a Toslink adapter). My understanding is that in my case the light came on because I was in the process of installing Windows and the driver for the audio hardware hadn't been installed yet.
GfulDedFan wrote:
As far as harmful rays, I doubt that it would be harmful because I've read about this audio problem before but never with a cornea damage attached to it.
I did look inside the jack directly at the light. I think it might be the retina that would be at risk if anything, but in any case, I sure hope nothing was damaged.
JoeyR wrote:
The power for the lasers used for digital audio is very low.
Is it a laser?
JoeyR wrote:
Especially if you didn't find it uncomfortably bright.
I don't recall having a reaction that it was uncomfortably bright and then having to force myself to look at it. If it had seemed uncomfortable I don't think I would have continued to look at it.
I don't think I actually became concerned about it until I found out that the light is for digital audio output and wondered if it is a laser. Not that I recommend looking right at a bright LED either. But I wasn't expecting a bright LED either (let alone a laser) -- like I said, my first thought was that there must be an LED inside to make the jack easy to locate in the dark (I was in a darkened room at the time.
JoeyR wrote:
If you've ever, even very briefly, had a low power laser pointer hit your eye, you'd realize it is super bright.
Fortunately I haven't, but someone who did have a laser pointer aimed at their eye told me they noticed it when they felt a burning sensation on their eye.
JoeyR wrote:
Any damage would almost always be nearly immediate. If you haven't had a problem, you're fine.
Do you think any damage would be readily apparent right away, in the form of pronounced discomfort or noticeable vision problem?