Exposure of a person’s eyes to a momentary sweep of Class 2 or Class 3 laser beam can result in temporary flash blindness, afterimage and glare which can be particularly dangerous if the individual is engaged in a vision-critical activity. There are documented cases of retinal damage following multi-second exposures to Class 3R laser pointers.

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Class 1 lasers are not sufficiently bright to be of use as pointers and therefore laser pointers are Class 2 or Class 3R. The latter emits up to 5 mW and they will produce exposures that can damage the eye faster than one can blink. The United Kingdom has banned the sale of Class 3R laser pointers although they are legal in Canada and the United States. A number of State and local governments in the U.S. have enacted regulations to limit the use of Class 3R pointers.

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Improper use of a laser pointer by failing to follow the safety precautions can cause eye damage and such practice is not acceptable. Improper use may create conditions that endanger the health or safety of others, and includes disruption of classes through playful scanning of beams, even though no injury results. Those misusing laser pointers may be subject to disciplinary procedures under the Code of Student Conduct or the appropriate staff policies or be subject to possible legal action if injury results.

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Laser pointers have been used in lecture theatres for a number of years and when used in a responsible manner they can be an effective tool. Recently, due to price reductions, these devices have been marketed widely as novelty items and complaints have been received about their inappropriate use by some attendees during lectures.

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Ultrafast optics is concerned with the generation, amplification, manipulation, and applications of femtosecond (10-15 s) pulses of light. The University of Michigan is home to the Center for Ultrafast Optical Science, which is an interdisciplinary research center in the College of Engineering and one of the leading laboratories in the field. Research areas at CUOS include ultrafast high power fiber lasers, applications of femtosecond pulses to semiconductor optoelectronics, quantum structures, materials science, micromachining, biophotonics, nanophotonics, and high field science. CUOS is home to the world’s highest intensity laser, HERCULES, which has demonstrated 1022 W/cm2 peak intensity on target. Applications of ultra-intense lasers include relativistic optics, laser-plasma interactions, laboratory astrophysics, electron and ion acceleration, and short-wavelength generation. CUOS has active interactions with many other UM laboratories and centers, including the Nuclear Engineering and Radiolocical Sciences department, the Biomedical Engineering and Materials Science and Engineering departments, the Michigan Nanotechnology Institute for Medicine and Biological Sciences, and the Michigan Nanofabrication Facility.

Lasers, an acronym for Light Amplification by Stimulated Emission of Radiation are an extremely bright source of light. A 1 mW visible laser is about one million times more brilliant than a 100 W light bulb and such light can, under certain conditions, cause damage to the eye. Lasers are classified into four main classes to identify the risk associated with them. Class 1 represents the least hazardous where exposure of the eye to direct or reflected beams is not expected to produce any damage. Class 2 lasers have an output of up to 1 mW and do not damage the eye when the exposure to the eye does not exceed 250 milliseconds. This is normally the time that it takes to react to a bright source of light and close one’s eye (the blink reflex). Class 3 lasers are subdivided into Class 3R (output < 5 mW) and Class 3B (output > 5 mW). Class 3 and 4 lasers can damage the eye in a time shorter than the time that takes to blink and because of this Class 3B and 4 lasers are subject to strict controls under the University’s laser safety program.