1. Excitement, fear or mood fluctuation: When people feel excited, afraid, worried or nervous, the sympathetic nerve will be stimulated, causing pupils to dilate.
2. Low light environment: In the dark environment, because the photoreceptor cells of the retina need more light to receive signals, the pupils will be enlarged to receive more light.
3. Side effects of some drugs: some drugs (such as atropine, cocaine, penicillamine, etc. ) will cause pupils to dilate.
4. Head injury or brain disease: This situation is very dangerous and requires timely medical treatment.
In order to protect our eyes, we can take the following measures:
1. When looking at the electronic screen, try to keep a certain distance and avoid staring at the screen for a long time.
2. Pay attention to indoor lighting and keep the light moderate.
3. Avoid using inferior glasses and counterfeit products, and replace glasses in time.
Eating more nutritious foods, such as vitamins A, C, E, vegetables and fruits, helps to keep your eyes healthy.
5. To avoid excessive use of eyes, you need to rest your eyes frequently, blink and stay away from strong light and high brightness environment.
Generally speaking, we should pay attention to protecting our eyes at ordinary times, so as not to cause too much burden to our eyes and avoid the occurrence of eye diseases. It's best to go to the hospital regularly to check our eye health. If there is sudden mydriasis, you should seek medical attention in time so as to find and treat related diseases in time.