The safety of laser pointers: myths and realities
Over the past few months an increasing number of reports have appeared in the popular press, describing incidents in which individuals claim to have suffered eye injury as a result of misuse of laser pointers.1 Such reports usually include a degree of media hype, together with descriptions of unlikely symptoms from indignant victims. The claims and counterclaims of occupational health and environmental safety agencies unfortunately do not attract the same degree of media interest or coverage. Motivation for the claims of individual victims are varied and include fear, ignorance, and perhaps avarice. Past experiences have shown that many individuals are truly fearful of the potential consequences of having momentarily viewed a laser beam and, therefore, seek professional advice or counsel. Other individuals are ignorant of any potential health effects, but are moved to seek advice by the group counsel of colleagues. Finally, some individuals may entertain the hope that litigation could give rise to large sums of money in settlement of personal injury claims. Given both the confusion generated by media coverage and the resultant demand on ophthalmic services in accident and emergency units, it may be helpful to review laser pointers and their interactions with ocular tissues, together with the potential confusions in international laser safety criteria.
In all laser safety documents the eye is of prime interest for two reasons. Firstly, the eye is the only organ of the body that allows optical radiations, from 400 to 1400 nm, to penetrate deep within it. Secondly, the refractive properties of the cornea and lens result in an increase in irradiance (W/cm2) in the passage of optical radiation between the cornea and the retina of up to 105. This increase in irradiance means that a laser achieving an irradiance of 1 W/cm2 at the cornea …
