The studies concerning the effects of pesticides on the human body focused mainly on their local action or chronic poisoning of the organism. In this study we examine the pesticide penetration into the eyeball resulting from direct contact with the eye. We used an isotope-labelled carbamate pesticide -- carbaryl. The determinations of the amount and concentration of this substance in the cornea, aqueous humour, vitreous humour and retina were performed using the method measuring beta radiation emitted by radioactive carbon. The results revealed measurable concentrations of labelled carbamate in the cornea and aqueous humour 10 and 30 min after application. The levels of this pesticide in the vitreous humour and retina were very low and difficult to analyse statistically. The described method appears to be useful in determining the range and rate of eye penetration by environmental toxins having direct contact with the eyeball.