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Japan: Teen injured by LED pen "toy" held 40 seconds in his eye

NOTE: The injury described herein was NOT caused by a laser but by a light-emitting diode (LED). We are including it here because the measured power of 5 mW is similar to laser pointers, and because in mid-2013 the FDA proposed to regulate toys containing lasers. This case of an LED-caused injury may stimulate arguments on both sides. Additional discussion is in blue at the end of this story.

A December 2006 incident has come to our attention. A 15-year-old Japanese boy suffered a retinal injury and visual loss after deliberately looking into a 5 mW violet (410 nm) light emitting diode for a total of about 40 seconds. The LED was in a pen was sold as a toy called “Secret Pen”. The toy appears to consist of an LED light which can excite ink that is invisible under ordinary light but which fluoresces under ultraviolet and near-UV light. The 410 nm wavelength caused photochemical damage to the retina.

According to a 2011 paper in Retinal Cases & Brief Reports, the LED was aimed into the teen’s eye from a distance of about 1 cm. It was held there for about 20 seconds as he deliberately stared into the light. This exposure was repeated the next day. About two weeks later, decreased vision (20/50 on the Snellen scale) was noted in the right eye.
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