[Changes in the dark focus of accommodation in patients with asthenopia].

The authors studied tonic accommodation in cases of asthenopia. The subjects consisted of ten college students, aged 20 to 22 years old as normal control and seven patients with asthenopia, aged 20 to 27. The dark focus of accommodation was measured with the infrared optometer before and after a 15 min sustained visual task. No significant differences were found between the two groups on the pre-task dark focus of accommodation. After the task, significant differences were found between the pre- and post-task dark focus of accommodation in patients with asthenopia. The results suggest that the patients with asthenopia are more susceptible to autonomic nervous system imbalance than healthy persons.