If eyes are exposed to IR within the distance of 2cm for more than 10 seconds, it might be harmful to your eyes. However, Iris scanning of S8/S8+ devices operates at a distance of 20cm~35cm within 1 second.
If you look at the iris recognition LED for more than 10 seconds or you are too close to it, the device will automatically stop iris recognition to protect your eyes.
There is no harm for human eyes.
In addition, IR LED of the Iris scanner of S8/S8+ achieved safety certification of the highest level “Exempt” based on the international standard IEC 62471. (IEC: International Electronical Commission).