Infrared and Corneal Eye Limits

ICNIRP 2013 eye exposure limits at any wavelength from 180 nm to 1 mm: corneal, anterior-eye and retinal limits with their apertures, and the largest safe power for an exposure time.

Model: Exact

Educational only — not compliance-grade

These pages implement the published exposure limits for the cases each one states, but they are educational tools: no laser safety officer has signed them off.

  • Do not use these results alone for PPE selection, NHZ / NOHD approval, controlled-area sign-off, enclosure/interlock approval, or formal classification.
  • Always verify against ANSI Z136.1, IEC 60825-1, your local procedures, and the responsible laser safety officer / CLSO.

Governing limit

Cornea (IR)

Max power for this time

15.4 mW

Power / max power

649× (exceeds)

LimitAperture (mm)H at t (J/m²)H/t (W/m²)Beam irradiance compared (W/m²)Max power
Cornea (IR)3.501000010006.49e+515.4 mW

The photochemical limit applies from 10 s; before that only the thermal limit does.

Exposure limits for the eye from ICNIRP 2013 (Health Phys. 105:271, Tables 3, 5, 7 and 8) for a point source and one exposure of 1 ns to 30 000 s, at every wavelength from 180 nm to 1 mm. In the UV and from 1400 nm the cornea absorbs the beam: 1 mm aperture below 0.35 s, growing to 3.5 mm at 10 s (11 mm from 100 µm). From 400 to 1400 nm the eye focuses it on the retina, averaged over 7 mm (the pupil), with C_A raising the limit up to 5× in the near IR and C_C from 1150 nm; twice the skin limit protects the cornea and lens (3.5 mm) and takes over as C_C rises towards 1400 nm. The beam is a round Gaussian centred on each aperture; the max power is the largest that stays within the limit at every duration up to t. A smaller pupil does not raise the limits. Not covered: pulse trains and extended sources. A beam under 1 mm (1/e diameter, d/√2 for the 1/e² d) is held to its peak on the cornea below 0.35 s (ICNIRP 2013 Table 5 note c).

Largest power of this beam within each limit, against exposure time. The beam is within the limits up to the time its power line meets the lowest curve.

Model and references

Exact. The equations are exact within the stated assumptions, or are a standard's tabulated values. The results are as good as the inputs. About the tiers

ICNIRP 2013 point-source eye limits (180 nm – 1 mm, 1 ns – 30 ks) for a round TEM₀₀ beam centred on each averaging aperture (its peak if under 1 mm (1/e) on the cornea below 0.35 s, ICNIRP Table 5 note c). Not modelled: pulse trains, extended sources.

  1. ICNIRP (2013). Guidelines on limits of exposure to laser radiation of wavelengths between 180 nm and 1,000 µm. Health Phys. 105(3), 271–295. Tables 3, 5, 7 and 8. doi:10.1097/HP.0b013e3182983fd4
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