Discussion and Support for the OptiTrack, SmartNav and TrackIR brands by NaturalPoint

Dangerous to damaged eyes?

Here you can talk about SmartNav and related products and issues not covered by other forums.

by JudyC » Sat May 12, 2007 9:13 am


My mother is suffering from ALS since 2 years and she is now rapidly using the ability to use her hands.
A friend told me about Smartnav, but I have heard that it uses infrared lights. My mother is also suffering from a cataract and I am afraid that the infrared might be dangerous to her eyes.
Can you please tell me if it might somehow affect her eyes even more and if SmartNav is approved by the food and drug association for safety?

Thank you,

Judy Cessarich
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Joined: Sat May 12, 2007 9:04 am

by tb220 » Sun May 13, 2007 11:53 am

I have very sensitive eyes, and I had trouble working with smartnav for more than an hour without getting fatigue. What I did is to mount the smartnav about a meter above me, and have it look down at me at a steep angle. I also used the smartnav hat. This way the infrared beam had no direct path towards my eyes, and my eyes never get fatigue anymore.

Best wishes to you and your mother.
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Joined: Sun May 13, 2007 11:46 am

by VincentG » Mon May 14, 2007 1:21 pm

The TrackIR/SmartNAV operates by tracking reflected or emitted IR light that is imaged by a CMOS sensor. The sensor and emitters are tuned to 880nm, slightly above the visible spectrum, you can see them emit a slight glow when the room lights are off, and this is the very upper end of the red spectrum. The sensor and IR LEDs are covered by a very special plastic that we custom designed with Bayer to block all light below 820nm, it passes all light above this point, it is called a band pass filter.

The LEDs emit at 880nm and are standard off the shelf IR LEDs; we run them all the time when the unit is turned on. There are 4 of them and they each have a total radiant output of about 23mw/sr, which is 23miliwats per ster radian. Total output power is NOT 4 X 23 mw/sr as the LEDS do not overlap exactly; they create a coverage pattern with slight overlap at the edges. Also, the LEDs to not emit a uniform brightness, they have an angle to half intensity, so the center of the overlapping LEDs is the SAME brightness as the center of each LEDs output, hope that makes sense.

Your eyes ARE sensitive to IR light, you can't see it, but your eyes will register the "power" of the light, your pupils will shrink down as if you were looking at light in the visible spectrum. Remember, we are just slightly above red in the visible spectrum. You won't feel your pupils getting smaller when our device turns on because we are a relatively low level of light for an average room condition. If you turn out all the lights in the room, put the unit about 1 foot away from your face and watch your eyes in a mirror, you will see your pupils contract, they are "seeing" the IR light.

As for the amount of power the LEDs output, it is many of times lower than simply going outside, not to mention on a bright sunny day. As I had seen posted before, we are a small fraction of the IR output from a normal incandescent light bulb. ANSI references spec ANSI Z 136.1 - 2000 for laser power emission, but we are not a laser, so in the back of the spec they reference ANSI/IESNA RP-27.1-96, which is the spec for lamp output, basically what we are and what ANSI says to use. Maximum exposure for our wavelength range, which is from 700nm to 1100nm is 10mw/cm2. To convert our power output, which is about 30mw/sr, we apply sr x 1cm2/distance2. Typical user distance is 18" or about 45cm (on the conservative side, most users are further away), so 30mw/2025 = .015mw/cm2. Needless to say, we are on the safe side!

If you have any further questions or concerns please let us know.
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Location: Corvallis, Oregon

by hihermes » Wed Sep 07, 2011 7:23 pm

i have very sensitive eyes
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Joined: Wed Sep 07, 2011 7:19 pm

by NaturalPoint - Mike » Thu Sep 08, 2011 10:43 am

If you have concerns about the output of IR light from the TrackIR, might I suggest the TrackClip Pro? When using the Pro, the lamps are on you and shine away. Camera mounted lamps are disabled.
NaturalPoint - Mike
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Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

by BittieDah » Tue Mar 28, 2017 6:41 pm

Having it slightly above your head has helped my cousin tremendously. He tries not to use it more than 4 hours a day though. He has very sensitive eyes.
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Joined: Tue Mar 28, 2017 6:38 pm

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