Routine fundus examinations require dilated pupils, but for specific patients and populations they cannot be dilated. In patients with glaucoma, the anterior chamber is shallow and the intraocular pressure is high. If the pupil continues to be dilated, the pressure will increase further, causing atrophy of the optic nerve in the fundus. In addition, it is not possible to dilate the pupil in children with a more transparent lens and a more cooperative examination. If a lesion is found in the fundus, a dilated pupil examination must be performed because the dilated pupil will allow for a wider range of vision, a relatively large number of areas to be examined, and more careful observation. This is why dilated pupils are a routine part of our eye examinations.