Mydriasis eye, and also to reduce painful ciliary muscle spasm (see cycloplegia). One effect of administration of a mydriatic is intolerance to bright light (photophobia). Purposefully-induced mydriasis via mydriatics is also used as a diagnostic test for Horner's syndrome. Mydriasis can be induced via modulation of adrenergic or cholinergic signalling. Within the adrenergic system, norepinephrine is a hormone and neurotransmitter responsible for regulating physiological processes in the body, including the involuntary muscles of the autonomic nervous system (such as the dilation or constriction of the pupil aperture via the muscles of the iris). Modulation of norepinephrine signalling can induce mydriasis. For
What Is Art? What Is Art? What is Art? ( "Chto takoye iskusstvo?") is a book by Leo Tolstoy. It was completed in Russian in 1897 but first published in English due to difficulties with the Russian censors. Tolstoy cites the time, effort, public funds, and public respect spent on art and artists as well as the imprecision of general opinions on art as reason for writing the book. In his words, "it is difficult to say what is meant by art, and especially what is good, useful art, art for the sake of which we might condone such sacrifices as are being