Iilensi ezitshintsha umbala ziba mnyama xa kukhanya ilanga.Xa umbane uphela, ukhanya kwakhona.Oku kunokwenzeka ngenxa yokuba iikristale ze-halide zesilivere ziyasebenza.
Phantsi kweemeko eziqhelekileyo, igcina iilensi zicace ngokugqibeleleyo.Xa ibonakaliswe ekukhanyeni kwelanga, isilivere kwikristale iyahlukana, kwaye isilivere yamahhala yenza ama-aggregates amancinci ngaphakathi kwelensi.Ezi zidibanisi zesilivere zincinci aziqhelekanga, zidibanisa ezidibeneyo ezingakwazi ukuhambisa ukukhanya kodwa zifunxe, zibe mnyama lens ngenxa yoko.Xa ukukhanya kuphantsi, i-crystal reforms kwaye i-lens ibuyela kwisimo sayo esikhanyayo.