blurry spot in my eyes...

[325addict]

Yes, I know, I've been stupid

Right after receiving my CR2 mini warm white light, I somehow managed to get that beam right in my left eye, reflected via the screen of my computer

It was on an extremely high "HIGH" at that moment, running off a LiFePO4 cell that won't sag under load....

When I blink my eye and look at a white wall, I see some round, dark spot with a small square in it... you'll recognize this as a reflector with a LED in it!

furthermore, when I look at the screen where I'm typing this right now, two words where I exactly look at, are blurry. When I look at a red old-fashioned LED 7-segment display, the intensity as well as the sharpness of it are less than with my other eye.

Question: did anybody have the same, and, more important, did it go away over time? I've had this for a few days now...


Timmo.

 

[HOLONYAK]

Yikes. I bet you will recover, but whenever I get a decent light I will treat it as a loaded Red Ryder!oo:

 

[AnAppleSnail]

It's likely to go away. Don't mess with high-power LEDs - make a doctor appointment.

Fine print:
Eye damage comes down to energy hitting the retina. At some point permanent damage is done - but before that, the chemicals in your rods and cones are fatigued and stop working for a while where they were nuked. Get the eye doctor appointment because he can tell you what to do. Blue lights do not effectively activate the human blink reflex. Some research shows that white LEDs, with their high blue content, don't activate the blink reflex appropriately for their brightness (Your eye reacts as if it were a dimmer light). This seems to me that it could increase the damage slightly - but the moral of the story is, don't look at bright lights!

 

[Sgt. LED]

You have done damage.
Seek medical advice now.

 

[Narcosynthesis]

Your eyes will hopefully recover with time, but with something as essential as your sight it isn't worth wandering about - get yourself to a professional who can check you out properly.

 

[325addict]

@ Sgt. LED: can you explain some more? You seem to be quite sure, I damaged my eye

I'll first go to some shop where they can measure eyes. This shop seems to be very good, they have several apparatus with which they can measure all kinds of sight-defects (in order to exactly know what kind of glasses or lenses you need...)

Timmo.

 

[fishhead]

You've had it for days? That doesn't sound good.

Get to the doctor, now. He or she can help you far better than us random folks on the internet.

 

[ODatsBright]

We've all (I'm reasonably sure) done this to some extent. You just HAVE to see how bright a light is right?

It usually goes away in a few minutes to a few hours. If you've had this for DAYS, get to a doctor! I can't image a mini @ 160 or so lumens would have done that much damage with just a quick exposure...how long did you look at the light like that?

 

[Helmut.G]

edit: reread your post.
You have had this for a few DAYS? go to a specialised doctor IMMEDIATELY!

what kind of flashlight is that? I figure as it's CR2 it has got a very small reflector? what was the distance flashlight-screen and screen-eye?

I guess the distances were extremly short, because I can't imagine such an extreme damage. Even the worst spots like this I had had disappeared completely after less than 15 minutes.

 

[325addict]

The spot is still there. The shape of it is no longer sharp round, and the square shape of the LED is no longer clearly visible. The blurry vision of the spot I look at still remains. All other things, just outside that small circle, can be seen sharp! It's just that small circle, exactly the spot I look at.
I didn't look straight into the flashlight itself, it was reflected by my computer screen. It was just a glance!
I think it was way brighter than the specs say it is. It was ridiculously bright when driven from a LiFePO4 cell. It was on high when the beam hit my eye...

There was one other event that took place at more or less the same time: some insect came into my eyes during cycling, it HURT like never before! Maybe this beast created the damage? That would, however, not explain that "round-shape-with-square-LED-in-it" I saw a few days ago...

Tomorrow, after work, I'll visit these optic guys, and I hope they can tell me more. I'll take that flashlight with me, as well as telling the story about that insect in my eye...

to be continued,

Timmo.

 

[Helmut.G]

what kind of led does the light use? I haven't read actively in the last time, don't know much about that flashlight, can you give some links?

is the spot in the center of your vision or off-center? as I understand your first post, it's in the center, right?

that insect story is also strange, but definitely didn't cause the light-source-shaped spot on your retina.

 

[AnAppleSnail]

what kind of led does the light use? I haven't read actively in the last time, don't know much about that flashlight, can you give some links?

is the spot in the center of your vision or off-center? as I understand your first post, it's in the center, right?

that insect story is also strange, but definitely didn't cause the light-source-shaped spot on your retina.

Edit: I don't know what I'm talking about with the MiNi regulation. Ignore my comments about it!

A MiNi CR2 driven on a LifePO4 battery should be in regulation while on High - unless the switching regulator is extremely sensitive to voltage it shouldn't be much brighter than with a regular CR2. It's an XP-G in the Q4 bin:
MiNi CR2 product page

325_addict, it's a good sign that the LED imprint on your eye is fading. You should still get it checked out by a doctor. There are many types of eye damage - let's hope this isn't the type that will keep you company for years.

 

[325addict]

As far as I understood from a thread by 4sevens, this light is NOT constant-power regulated. Some guys tell me, it is "voltage regulated". To me, this means nothing, it is not regulated the way we know (that is: applying a higher voltage will cause the current to DROP instead of to rise)
Here, it is the opposite: more voltage means more current, which means more power SQUARED!
I also noticed, the light runs extremely hot within the first few minutes, and it draws an enormous current: after 12 minutes, the battery is flat.

I just tried it using a regulated power supply:
2.7V -> 0.75 Amps
4.0V -> 1.0 Amps

The higher I turned up the voltage, the more current this thing draws... meaning it is NOT regulated.

So, by using a STABLE energy source, it may very well come well above what 4sevens specify in output I'm afraid...

The blurry spot is going into the direction I look in. It is no "fixed" point, it is exactly in the "sweet spot" of looking!

I hope they will find out more tomorrow....


Timmo.

 

[jabe1]

The MiNis are voltage regulated, and not current regulated.

The Mini's are not current regulated. They are voltage regulated (brightness varies with input voltage) coupled with PWM for output adjustment.

 

[Helmut.G]

As far as I understood from a thread by 4sevens, this light is NOT constant-power regulated. Some guys tell me, it is "voltage regulated". To me, this means nothing, it is not regulated the way we know (that is: applying a higher voltage will cause the current to DROP instead of to rise)
Here, it is the opposite: more voltage means more current, which means more power SQUARED!
I also noticed, the light runs extremely hot within the first few minutes, and it draws an enormous current: after 12 minutes, the battery is flat.

I just tried it using a regulated power supply:
2.7V -> 0.75 Amps
4.0V -> 1.0 Amps

The higher I turned up the voltage, the more current this thing draws... meaning it is NOT regulated.

So, by using a STABLE energy source, it may very well come well above what 4sevens specify in output I'm afraid...

The blurry spot is going into the direction I look in. It is no "fixed" point, it is exactly in the "sweet spot" of looking!

I hope they will find out more tomorrow....


Timmo.

ok, it's not regulated, but still it shouldn't be dangerously bright even at more than 1 A LED current. I simply can't imagine that kind of damage.

how close to the light was your eye?

 

[325addict]

That's what I mean... "voltage regulated" can as well be replaced by "voltage dependent" or "voltage controlled" because there's nothing "regulated" here...

To me, "voltage regulated" is a hollow phrase.... just like "cleaning alcohol". There's just one alcohol... alcohol!
And there's just one way of regulation in a flashlight... the way in which the LED always has a constant power, regardless (to some degree, of course) of the input voltage.
As the LED Vf is fairly constant, you could do with a constant current source. This will, however, not be an efficient way, as the current remains the same, fresh batteries or nearly depleted.

A true, constant power regulated light can immediately be recognized when you hook up a regulated power supply: turning up the voltage from zero, current will start to rise (the LED will light with an ever increasing strength) then, from a certain point (from here, the light is "in regulation") output remains constant and current will start to fall when you turn up the voltage further from this point.

In case you see an ever-increasing current when turning up the voltage, the light is NOT regulated in any way. Period.

@ Helmut: the light was 30 to 40cm away from the computer screen. My eyes had a normal distance to that screen, let's say 50 to 60cm?

Timmo.

 

[AnAppleSnail]

That's what I mean... "voltage regulated" can as well be replaced by "voltage dependent" or "voltage controlled" because there's nothing "regulated" here...

@ Helmut: the light was 30 to 40cm away from the computer screen. My eyes had a normal distance to that screen, let's say 50 to 60cm?

Timmo.

The regulation used is switching regulation - That is, each power level is made by PWM. This makes sense by testing, because the MiNi AA can be made ludicrously brighter at all levels with a Lithium-Ion battery. LEDs that are fed extra voltage suck more current - so the LiPO battery that doesn't drop much in voltage blasts more current through the LED, leading to higher output. "Medium" and "Low" rapidly flicker the LED so that it's on part of the time - but when the LED is on, it probably gets the same current that 'high' gets. I'm not sure, but I think that the PWM circuit here is direct-drive when it's on. Maybe not, I'm seeing that I really don't know my drivers very well.

PWM control is much cheaper than constant-current, and considering that the MiNi line is essentially a supertiny light for not so much money, it's the best choice. If someone here can guess what the XP-G will do in direct drive with a LiPo battery, we'll have an idea of how many lumens you got.

The fuzzy spot is probably on your retina - it's chemical fatigue in the eye, or it's damage. Either way, it'll be exactly in the same part of your field of view because it's stapled to your eye.

 

[Ragiska]

That's what I mean... "voltage regulated" can as well be replaced by "voltage dependent" or "voltage controlled" because there's nothing "regulated" here...

To me, "voltage regulated" is a hollow phrase.... just like "cleaning alcohol". There's just one alcohol... alcohol!
And there's just one way of regulation in a flashlight... the way in which the LED always has a constant power, regardless (to some degree, of course) of the input voltage.
As the LED Vf is fairly constant, you could do with a constant current source. This will, however, not be an efficient way, as the current remains the same, fresh batteries or nearly depleted.

A true, constant power regulated light can immediately be recognized when you hook up a regulated power supply: turning up the voltage from zero, current will start to rise (the LED will light with an ever increasing strength) then, from a certain point (from here, the light is "in regulation") output remains constant and current will start to fall when you turn up the voltage further from this point.

In case you see an ever-increasing current when turning up the voltage, the light is NOT regulated in any way. Period.

no, that is INCORRECT. you have NOT done your research, and voltage regulation IS a type of regulation. voltage regulation does NOT hold the POWER constant as you wrongly ASSUMED. and no, the Vf of the LED is NOT constant, it varies with forward current.

To me, "voltage regulated" is a hollow phrase.... just like "cleaning alcohol". There's just one alcohol... alcohol!

you mean like ethanol, methanol, isopropyl, propanol, butanol, etc??

for one, try doing your research BEFORE making erroneous statements!!

 

[march.brown]

There is always the possibility that there was already some weakness with your sight ... Something that you didn't know about that was shown up by your encounter with the bright torch.

I have on occasion done a similar thing with some of my torches ... The worst was with about 200 lumens ... My sight was restored within a couple of hours maximum.

Your optician will be able to photograph the inside of your eye to show the optic nerve etc ... Be prepared for the very bright ring-flash used in this photograph ... The effects of this flash are gone in a couple of minutes usually.

The sooner you can visit the optician the better.

Best wishes for your speedy recovery.
.

 

[325addict]

@ Ragiska:

Here we go again....

FIRST, I did NOT say Vf is CONSTANT, it is FAIRLY constant, and... it IS that way, period!!
And... just read on, and you'll notice that I meant this when driven at a constant current. Driven this way, the Vf is even more constant. Just READ and UNDERSTAND what I wrote...

Second:

where Vnl is voltage at no load and Vfl is voltage at full load. A smaller value of VR is usually beneficial.



OK, so VR must be as small as possible for a good regulation, right? The equation above is just the way to determine if a regulated power supply is able to deliver a constant voltage with various loads on it - and as YOU, YOURSELF stated, that a flashlight is NOT a regulated power supply, well... WHY ON EARTH do you now link THIS?



A flashlight is, indeed, no regulated power supply.... this way of voltage regulation has NOTHING TO DO with the 4sevens lights mentioned here!!!!!!!!



And I state it AGAIN: these mini-flashlights are NOT REGULATED IN ANY WAY!!! It's just a free running oscillator at a voltage that comes in, various brightnesses are dealt with by adjusting the duty-cycle of the PWM-signal.
Maybe there's some kind of current limiter to prevent a blow, but that's about it. Most likely, even THIS is not in.



When you make the (FALSE!) statement that these light ARE regulated, then please tell me where I can find the:



A: control loop, with feedback for a certain value (parameter) to be kept constant (after all, that's what regulation is all about - to keep a certain parameter constant).



B: and, please tell me WHAT PARAMETER is "regulated".... it certainly is NOT the brightness, as I today noticed very simply... just apply an ever increasing voltage, and you get an ever increasing output! And... an ever increasing output means that NEITHER voltage, NOR the current are REGULATED in ANY WAY...........

This is the VERY PROOF these lights are NOT regulated at ALL - period!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


You can try to talk like wild, and try to get between this - every effort to do so is useless, I'm an electronics ENGINEER and I know EXACTLY when something is regulated and when it is not. To make the claim regulated, there MUST be some kind of regulation loop, with an error amplifier, that is constantly comparing a SET VALUE with the ACTUAL VALUE and, on top of that, the output of the error amplifier should be able to CORRECT and ADJUST the value of the parameter that is to keep constant, in order to close the loop.



I suggest YOU DO YOUR RESEARCH on WHAT REGULATION IN FACT IS!! When you know what the minimum parts/functions are for something to be called "regulated" well..... by that time you'll have noticed I am right here...

And YES, of course voltage regulation IS a way of regulation, but is has NOTHING TO DO with these flashlights!!! You just don't understand that voltage regulation is NO WAY to regulate a LED-light. It IS a way to regulate an INCAN-light, however.... LEDs are driven with a CURRENT, incans are driven with a HARD VOLTAGE.
I built an innumerable number of voltage regulators of all kinds (being discrete or with ICs) so I am exactly knowing what I'm talking about when it comes to voltage regulators....




Timmo.