Dilation

OVERVIEW

Do you think of getting your eyes dilated as a nuisance? We’ll be the first to admit that even though it’s painless, dilating your eyes is probably annoying at best. Maybe you’ve never really understood just what we’re accomplishing by putting those pesky drops in your eyes. Here’s your chance to find out.

Your eye exam begins with a thorough investigation of the lids, lashes, conjunctiva, sclera and cornea – the external surfaces. Using a microscope and a bright light, the doctor will move in for a closer look at the anterior chamber, iris and crystalline lens. The iris is very similar to the shutter of a camera. When you take a picture on a bright sunny day, the shutter becomes smaller, allowing less light to enter. Likewise, your pupil becomes smaller when we shine a bright light at your eye, making it very difficult to peer inside. That’s where the dilating drops come in.

Dilating drops work on one of two principles: they either stimulate the iris muscle that opens the pupil (the dilator), or prevent action of the iris muscle that closes the pupil (the sphincter). After the drops take effect, your doctor can get a much better view of your retina, optic nerve and vessels in the back of the eye. This is a very important part of your preventative eye care as well as some eye surgeries. From this simple step, we are able to gather a lot of important information about your eyes. In fact, some systemic diseases such as hypertension and diabetes are first discovered during the dilated eye exam. 

Some dilating drops also prevent accommodation. The natural lens is able to accommodate or adjust the eye’s focus until about the age of 40. Children and young adults are especially good at this, and their ability to accommodate sometimes prevents the doctor from getting an accurate refraction for glasses. That’s why young eyes are often dilated for a “wet” refraction so the doctor can get a true picture of what the child’s prescription really is. 

There are a few things you can do to make your visit a bit more comfortable:

  • Don’t plan any activities after your appointment that require crisp vision.
  • Bring along a pair of dark sunglasses for the ride home.  Don’t worry if you forget yours, just ask for a disposable pair as you check out.
  • If you know you’ll have trouble seeing to drive home (even with the sunglasses), please bring a friend.
  • Bring a newspaper, book or magazine with larger print to read after the drops begin to work.