Laser sensing systems such as LiDAR and NLOS increasingly use light at a wavelength of
1550 nm, which is considered safer for the eye because it is absorbed in water before it can
reach the retina. However, it can still damage the cornea. The exposure limits for such
wavelength are spread across various standards and guidelines, so a quick safety assessment
of a provided system is not possible. We reviewed the literature and compiled the maximum
permissible exposures for continuous wave lasers, single pulses and repetitive pulses into
tables and compared them with experimentally determined corneal damage thresholds. We
then examined the safety of two published NLOS systems. The maximum exposure is 100
mW/cm² for continuous exposure and 1 J/cm² for a single pulse in the duration range from
1 ns to 10 s. For repetitive pulses, the second rule is usually the most restrictive. For pulses
shorter than 1 ns no direct limit is specified.
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