Sense-organ qua efficiency- A type of Dravyendriya (physical sense-organ);
the physical capacity of the Nirvṛtti Dravyendriya (organic structure) of the sense-organ, which is the most essential means, responsible for making it responsive to comprehend its specific object.
visayaggahaṇasamatthaṃ uvagaraṇaṃ imdiyaṃtaraṃ taṃ pi.
jaṃ neha taduvaghāe giṇhai nivvattibhāve vi...
(ViBhā 2996)