Dilating eyedrops (called mydriatics) are used to dilate, or enlarge, the pupils of your eyes so that your eye doctor can see the inside of your eye in detail.
Dilating drops work in one of three ways:
- By temporarily paralyzing the muscle that makes the pupil smaller;
- By stimulating the muscle that makes the iris (the colored part of the eye) widen; or
- By preventing the pupil from adjusting for focus (called accommodation).
With your pupils dilated, your eye doctor can use special instruments to see the eye’s entire lens, which focuses light onto the retina (the light-sensitive tissue lining the back of the eye). The retina itself also can be seen, as well as the optic nerve, which sends signals from the retina to your brain where they are interpreted as images.
In addition to exams, dilating eyedrops are used for a variety of purposes. For some types of eye surgery, your ophthalmologist (Eye M.D.) will need to dilate your eyes. Sometimes, after certain types of surgery, it is important to use dilating drops to keep the pupil wide so that scar tissue won’t form. Your eyes may also be dilated to relax your lens’s focusing muscles so that your eye doctor can measure accurately for your glasses prescription.
Dilating drops are sometimes used in children who have amblyopia (lazy eye). Because the drops cause temporary blurry vision, they are used to blur the stronger eye, thereby forcing the child’s brain to use the weaker eye.
Next Page: What to Expect When Your Eyes Are Dilated