Dilation, pupil (test): Opening the pupil wide enables your eye care professional to see more of your retina, the light-sensitive layer of tissue at the back of your eye.
Dilating (widening) the pupil permits the retina to be examined for signs of disease. To do this, drops are placed into the eye to dilate (widen) the pupil. After the examination, your vision may (or may not) remain blurred and you may (or may not) be bothered by the brightness of the sun for several hours.
The pupil is the opening in the center of the iris, it is not a structure and does not move itself. It is the iris that dilates or constricts and enlarges or restricts the size of the pupil. The size of the pupil determines how much light is let into the eye.
Dilation is the process of enlargement or expansion. Things don’t just open in medicine; they dilate. The word “dilatation” means the same thing as dilation. Both come from the Latin “dilatare” meaning “to enlarge or expand.”
Dilator: A device used to stretch or enlarge an opening. Patients with scarring of the esophagus can require a dilator procedure to open the esophagus for adequate passage of food and fluids.
Dinucleotide: A sequence of 2 base pairs. A trinucleotide (a triplet of base pairs) may be split into a dinucleotide and a mononucleotide.
- Diogenes syndrome Medical Definition
Diogenes syndrome: a behavioral disorder that occurs in elderly people characterized by living in squalor, unhygienic living conditions, self-neglect, social isolation, lack of shame, and hoarding. Refusal of help and denial of the condition are common in people suffering from Diogenes syndrome. Diogenes syndrome is also known as senile squalor syndrome. The exact cause is […]
Dioscorides: Dioscorides of Anazarbus. First century Greek physician, botanist and pharmacologist whose encyclopedia of materia medica was used for centuries after his death. Born in southeast Asia Minor in the Roman Empire in the first few decades C.E. During his lifetime, Dioscorides traveled extensively seeking medicinal substances from all over the Roman and Greek world. […]
Dioxin: One of a number of poisonous petroleum-derived chemicals which are produced when herbicides (substances used for killing plants) are made or when plastics are burned. Dioxins are chemically dibenzo-p-dioxins. One of the best known is TCDD (2, 3, 7, 8-TCDD). Dioxins cause skin disease (chloracne). In animal tests, dioxins are teratogens (agents that cause […]