The safety limits that exist for human exposure of laser radiation are essential to reduce the risk of injuries. These values, however, give very little information on what tissue damages that may be expected at various elevated exposure levels. Similarly, the Swedish Radiation Protection Authority (SSM) has very little information on how such tissue damage is related to the impairment of the vision. This type of relationship between an imaginary exposure and a subsequent disability is very useful in the risk assessments that are made in the authority’s supervision activities. Also, the damage’s evolvement over time is information that the authority can make use of in risk assessments.
The purpose of this study was to investigate what dose of laser radiation, in terms of intensity and exposure time, may be associated with eye damages. The study has been limited to unwanted exposures of laser radiation from commercially available laser pointers. Of particular interest has been to search for data that clarify the dose-response relationships for functional disabilities that persist more than 6 months.
The study shows that long-term vision loss can occur as a result of involuntary exposure from commercially available (strong) laser pointers at close range. The injury may occur before a normal person is able to respond by closing the eyelid, although there are only a few cases reported. A minor such damage is transient within a few days. It is also likely that such a visible injury to the retina becomes functional, i.e. prevents reading skills. What dosage is required for the disability to become permanent is not clear in the literature. Also, the dynamics of evolvement and repair of tissue damages and disabilities are hardly described at all.