The disadvantages of dilated pupils often include blurred vision, photophobia, and triggering an acute glaucoma attack. 1. Blurred vision. Dilating the pupil of the drug can paralyze the ciliary muscle, suspensory ligament tightening to the lens is flat, refractive error, therefore, close things can not be clear imaging in the retina, resulting in patients with unclear vision. 2. Fear of light. Pupil dilation drugs can dilate the pupil, in the case of sufficient outdoor light, the patient may appear afraid of the phenomenon of light, manifested in squinting, covering with the hand and other actions. 3. Induce acute glaucoma attack. Dilating the pupil can cause the iris to move in the direction of the atrial angle, which can make the anterior chamber angle gap narrow, the atrial aqueous outflow channel is blocked, which in turn causes an acute increase in intraocular pressure and induces an attack of glaucoma. Pupil-dilating drugs need to be used under the guidance of a doctor, and if an acute glaucoma attack occurs, prompt medical attention is required.