Let There Be More Light was created on 1968-06-29.
Let in the Light was created in 2007.
Let There Be Light - film - was created in 1946.
Let There Be Light - book - was created in 2006.
Let Your Dim Light Shine was created in 1994.
Let the Light Shine Down was created in 1991.
God commanded let there be light and there was light.
In the beginning god said, "let there be light...'
The aperture.
To let more light in your eyes
Let Me Be was created in 2009.
Sorry, but I simply do not understand your question. What hold light are you referring to. And what do you mean by, "when you let go"? Please rephrase the question with more detailed information.
In dim light, your pupil expands. In bright light, your pupil contracts. Your pupil contracts in bright light because not as much light is needed to see. Same thing with dim light, your pupil expands in dim light because there is more light needed to see. Because there is not as much light in a closet than in an open field your pupil contracts and expands to let in more light or let in less light, depending on were you are at and how dark it is.