Material and Method: Twelve children acutely exposed to elemental mercury as a result of a broken thermometer (2x20 cm in size) in the science laboratory that was undiscovered over one day were included to the study. The amount of exposed mercury was about 1 ml. Age- and sex-matched 13 healthy children were employed as control group. Full-field ERG recordings were performed following a detailed ophthalmological examination for all cases and the recordings were compaired.

Results: Best-corrected visual acuity was 10/10 in all children. Mean intraocular pressure was 14.9±1.7 mmHg (13-16). No significant change was detected in any children in fundus examination. In the comparison of ERG parameters between patient and control groups, rod amplitude, maximum combined response amplitude, oscillatory potential amplitude and cone amplitude of both eyes were significantly lower in the patient group than the control group (p<0.05).

Conclusion: Elementary mercury can be found in many daily using tools. The result of unsuitable usage of this tools especially children can exposure of mercury. Acute mercury intoxication can affect all systems also with visual system. Therefore, all employee and students should be aware of the tools containing mercury and toxicity risk of mercury especially in the schools. Keywords : Mercury toxicity, neurotoxicology, electroretinography