This paper summarizes three experiments, these results and discussion. The first series of
experiments were performed in order to research eye irritation caused by photochemical synthetic
irritants. They proved the threshold of eye irritation and the grade of irritable pollutants. Effects
of photochemical air pollution on the human eye were epidemiologically investigated in the second
series of experiments. Tear lysozyme and tear pH were chiefly traced as factors of the affected
eye. In the third series of experiments, hen egg lysozyme was examined under various synthetic
pollutants to seek what substances reduce the tear lysozyme. As a result, it has been suggested
that ozone(03) was primarily responsible for its reduction under photochemical smog. Finally
in this paper, it has been discussed why ocular symptoms and signs occurred in photochemical
smog.