Do progressing myopes show reduced accommodative responses?

Refractive error and accommodative responsivity were monitored at 4-month intervals over a 1-year period to determine whether an increased lag of accommodation either precedes or accompanies the development of myopia. Accommodation was measured for stimulus levels of 2.5, 3, 4, and 5 D, and both the slope of the stimulus-response function and accommodative error were computed. Almost all subjects exhibited accommodative stimulus-response gradients close to unity, although a lower gradient was observed in subjects who were myopic upon entry into the study and whose ametropia remained stable. These stable myopes also exhibited the largest lag of accommodation. These findings do not support the proposal that the development of myopia in young adults is accompanied by a reduced accommodative response during nearwork.