undilated

Undilated refers to a state where something has not been expanded, enlarged, or mixed with another substance. In medicine, the term is most commonly used in relation to the pupil of the eye. An undilated pupil is the normal size it appears when not exposed to dilating drops or significant changes in light. When a doctor examines the eye, they may use dilating drops to enlarge the pupil, making it easier to view the retina and other internal structures. If the pupil remains at its natural size, it is considered undilated.

The term can also be applied more broadly. For example, a solution that is undiluted is in its pure or concentrated form, without any added solvent like water. This is in contrast to a diluted solution, which has had a solvent added to reduce its concentration. Similarly, an undiluted emotion or opinion would be one that is expressed without any softening or modification. In essence, "undilated" signifies a lack of expansion or reduction in concentration or intensity.