It is normal that some people have larger pupils while the others have smaller pupils. Actually, many people think larger pupils are more attractive. If your pupils are extremely large, you will be sensitive to light and find it difficult to drive in the night. However, this does not bother your eye health. If you are a teenager, it is also a normal phenomenon in this pubescent period. You can have your eyes tested if you really worry about your pupils. Get a flashlight and shine it in your eyes. In normal cases, the pupils will become smaller in the light and larger when the light is dim. If not, there must be something wrong with your eyes, and you should consult your doctor and get proper and timely treatment.
Go out into the sunshine and take out a mirror to see if your pupils are still large. Normally, the pupils get large in the dark and becomes smaller in strong light. If your pupils change its size photochromicly, they are fine.
If your pupil are large even in sunlight, there must be something wrong. It can be caused by medication. Did you just take some eyedrops which dilate your pupils? Did you eyes get injured recently? If so, those could be the cause and you need to go to see a doctor to solve this problem.
The pupil is mainly affected by the two groups of muscle innervations, when you are frightened or get emotional volatility, your pupils will become big because of sympathetic stimulation. In addition, it is normal for pupils become big when dim light enters eyes, so when you work at night, youâ€˜d better choose a brighter lamp to prevent bigger pupils. Another reason is the excitement of the parasympathetic nerve, when you breathe deeply or does too much brain work, it will cause big pupils owning to the parasympathetic nerve. In this case, please give yourself enough time to take a break.