Well, generally speaking, when dilated pupils occur, the black part of the eye will be bigger than normal. In other words, we can say that dilated pupils look like a big black circle. So just check it with your eyes. And in that way, your eyes may be painful in some degree. And also, if the cause is high blood pressure, it will just make your eyes feel stressed. By the way, some factors, such as high blood pressure and anxiety can cause pupils to be dilated. Besides, drug use, illness, and trauma are other causes. So just be careful about it.
It is bad to have dilated eyes. The side effects of dilation are experiencing glare, some sensitivity to light and some blurring of your near vision, also affecting your ability to drive. To reduce problems with light sensitivity and glare following dilation, it is necessary to wear a pair of sunglasses. If you wear contact lenses, you should change it with frame glasses.
If your dilated eyes are caused by the sudden surprise or the shock, they will be OK which will come back to the normal state quickly. However, if your dilated eyes are caused by the eye problems, they will be bad for the eyes. As we know, when you get the dilated eyes, your pupils will be open in the big state which allows the big chance for the bacterium to come into. You will get the high possibility of getting the eyes infection. You may also cause the eye nerves to be damaged during the dilated symptom. You'd better go to see the doctor and check the eyes because sometimes the dilated eyes are often happened because of the bacterium in the eyes. You'd better get rid of the eye problems and then you could avoid the dilated eyes to some degree. Or else, the dilated eyes will cause your eye problems to become serious.