What you need to know about dilated pupils

We’ve all experienced the odd sensation of having our pupils dilated during an eye exam. It’s a fairly common practice and it’s supposedly an important part of every eye exam. But why, exactly, do eye exams require dilation? What does dilating your eyes actually do?  

Let’s find out.  

What is pupil dilation?  

Your pupils dilate regularly throughout the day to adjust for lighting and distance. They shrink when exposed to bright light and expand in darker environments. They do this to change the amount of light reaching your retina. The more light reaching your retina, the more you can see. Your pupil does this automatically and is why it takes your eyes a few moments to adjust when going outside on a sunny day.  

Why is it part of my eye exam?   

When your pupils are dilated it provides a better look at your retina and is why your eye doctor will induce dilation during an exam. Having an open pupil lets your eye doctor see the overall health of your retina and check for any issues. Typically, the drops used by your eye doctor to induce dilation will wear off within four hours. During this time, you may find your vision to be slightly blurred and experience an increased sensitivity to light.   

When should I worry about dilated pupils? 

Light and eye exams aren’t the only reasons your pupils dilate. Certain medications are known to cause pupil dilation as a side effect. Consistently irregular, or mismatched pupil size, is something to not be taken lightly. There are many serious medical conditions that are associated with pupil dilation and should be investigated by a doctor.  

If you have noticed your pupils look different than they usually do, it’s best to be safe and seek medical advice as soon as possible.