Mydriasis More generally, mydriasis also refers to the natural dilation of pupils, for instance in low light conditions or under sympathetic stimulation. An informal term for mydriasis is blown pupil, and is used by medical providers. It is usually used to refer to a fixed, unilateral mydriasis, which could be a symptom of raised intracranial pressure. The opposite, constriction of the pupil, is referred to as miosis. Both mydriasis and miosis can be physiological. Anisocoria is the condition of one pupil being more dilated than the other. There are two types of muscle that control the size of the iris: the
Sum of normally distributed random variables variables is normal, with its mean being the sum of the two means, and its variance being the sum of the two variances (i.e., the square of the standard deviation is the sum of the squares of the standard deviations). If one is to get the conclusion that the sum is normally distributed, the assumption that "X" and "Y" are independent cannot be dropped, although it can be weakened to the assumption that "X" and "Y" are jointly, rather than separately, normally distributed. (See here for an example.) The result about the mean holds in all cases, while the result