Why You Need Your Eyes Dilated

by Nov 8, 2021

Each time you see your eye doctor, they will ask if you can be dilated. While many people hate dilation—the drops sting upon instillation, bright lights are shown into your now light-sensitive eyes, the inability to see up close for hours after your exam, and enlarged pupils are quite annoying—dilated eye exams are of utmost importance for evaluating the health of your eyes.

Even in today’s world with ever-improving technology with retinal cameras, dilated eye exams are still important. In fact, the only way to truly observe all 360 degrees of the retina is with a good old-fashioned dilated exam.


Eye Anatomy

To best understand why dilation is so important, it may be helpful to understand what doctors are looking at during dilation.

The backmost structure of the eye, called the retina, is essentially the most important part of the eye, as it is solely responsible for light detection and transmission of said light to the brain for image processing.

The retina contains 10 layers, each playing a pivotal part in the overall function of the retina.

You can think of the retina almost like a peg board. It is lined with millions of photoreceptors (specialized cells that detect light) that are stimulated when light rays lands on them.

These cells need to have direct access to light, nothing can be obstructing the path of light or the photoceptors will not be stimulated as they should, and images will therefore not be created properly by the brain.

This means blood vessels must be precisely located around the cells so that no vasculature interferes with the pathway of light.

This does not mean, however, that the retina does not require blood to survive. Like other cells within the body, the photoreceptors still need nutrients and oxygen that are provided by blood. The vasculature system of the retina is just extremely modified and organized so that it does not interfere with the photoreceptors.

Any kind of vascular change, infection, deposit build up, etc. alters the anatomy of the retina, and therefore runs the potential risk to interfere with vision. If a problem occurs for too long and photoreceptors die, they cannot regenerate, and the person will experience a permanent visual defect.

What complicates this all further is that there are no nerves within the retina. This means no pain is experienced when something goes wrong in the retina. The first noticeable symptom of retinal problems is vision loss, which cannot always be repaired if the photoreceptors have died.

Therefore, the only way to monitor for changes in retinal health is through an eye doctor looking at the retina. In fact, the eye is the only part of the human body in which a doctor can look into without requiring surgery, making dilation a useful tool not only for the eyes but for overall health detection as well.

Dilated eye exams allows eye doctors to do just this. Doctors use specialized light systems to look through your eye to gain views of the retina. To make this process easier, your doctor will need to make the pupil of the eye (the black part in the middle of the colored area) larger.

To put this into a different perspective, think about the pupil being a keyhole to the retina. If you have ever tried to look through a keyhole, you will note that it is quite difficult to get a large view to the other side. However, if you were to make this keyhole larger—say to the size of a peep hole—the view of the other side of the door becomes significantly larger and easier to view. Dilation does just that for doctors, and allows them to see all 360 degrees of retina.


What Diseases Can be Detected with Dilation?

During a dilated eye exam, doctors are looking at several different aspects of the eye. They want to observe the optic nerve (where information from the photoreceptors exit the eye and enter the brain), the macula (the area of the eye with the highest concentration of photoreceptors, which is responsible for your central vision), the blood vessels of the retina, and the health of the retinal periphery.

Here is a very brief list of some of the diseases that can be detected through dilation:

  • Glaucoma: Changes to the optic nerve can indicate cell death and potential vision loss if treatment is not initiated.
  • Swelling of the optic nerve: swelling of the optic nerve can be warning signs of something more serious including brain tumors, multiple sclerosis, elevated cerebral spinal fluid, or autoimmune diseases.
  • Macular Degeneration: a disease in which deposits accumulate below the macula, leading to eventual vision loss.
  • Diabetes: Diabetes can cause vasculature changes which may present in the eye prior to other parts of the body.
  • Hypertension: Like diabetes, hypertension can show signs in the eye prior to the rest of the body, as the blood vessels within the eye are more fragile than other blood vessels, making them more susceptible to early changes.
  • Retinal Detachments: Sometimes the layers of the retina can separate and pull away from the base of the eye. If this occurs it can cause permanent vision loss and must be fixed ASAP.

As you can see, dilation can provide a lot of insight to not only the health of the eyes but also the rest of the body! While it may be uncomfortable, it is a tool that provides immeasurable benefits as many times prevention is the key to good health.


How Often Should I Have my Eyes Dilated?

Dilated eye exams are recommended yearly for everyone, even those who have great eyesight and do not need glasses.

Many offices are now offering retinal photos in lieu of dilation. These photos are great tools to help doctors compare retinal changes over time, however they do not replace dilation. It is recommended that every individual get at least a retinal image taken each year, and if you opt to do photos only, dilation should be performed every 2-3 years.


Dr. Nathan Abraham and the staff of the Abraham Eye Center specializes in cataract surgery, LASIK, PRK, and various corneal surgeries.  Call our ophthalmologist in Valencia, CA today at 661-977-7377 or schedule an appointment online if it is time to have your eyes dilated and examined.  Our eye doctor provides only the highest quality eye care and surgical services amongst eye doctors in the Valencia California area.

Request Appointment

You can schedule your next appointment with us online!

Connect With Us

Let’s continue the conversation over on your social network of choice.


Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.