Jamieson, Fausset and Brown on Job 41:18

18. Translate: "his sneezing, causeth a light to shine." Amphibious animals, emerging after having long held their breath under water, respire by violently expelling the breath like one sneezing: in the effort the eyes which are usually directed towards the sun, seem to flash fire; or it is the expelled breath that, in the sun, seems to emit light.

eyelids of morning--The Egyptian hieroglyphics paint the eyes of the crocodile as the symbol for morning, because the eyes appear the first thing, before the whole body emerges from the deep [Horæ Hierogliphicæ 1.65. Bochart].