Fig. 2

Schematic illustration of LT changes relating to accommodation stimulus in CI IXT. Children with CI IXT tended to make greater accommodative effort to maintain binocular vision when fixating from distance to near task. The increase in LT was supposed to be resulted from tensing of ciliary body–zonules apparatus and pulling of lens during accommodation. Given the accommodative spasm and excess convergence related to near-task and ocular exodeviation, it is possible that the tense ciliary–zonules apparatus and thick lens during accommodation could have prolonged effect over time, thus observed by the device. Thick arrow displays the mechanistic insights and hypotheses. Thin arrow points to crystalline lens and ciliary body–zonules apparatus. IXT intermittent exotropia, LT lens thickness, CI convergence insufficiency