A standard diabetic eye exam takes about 30 to 90 minutes from check-in to walking out the door. The actual testing and examination portion is relatively quick, often 20 to 30 minutes, but the eye drops used to dilate your pupils need 20 to 30 minutes to fully take effect before the doctor can examine your retinas. That waiting period is what stretches the appointment.
What Happens During the Exam
A diabetic eye exam is more involved than a routine vision check. The primary goal is to look at the blood vessels in your retina, the light-sensitive tissue at the back of your eye, for signs of damage caused by high blood sugar over time.
The appointment typically starts with basic vision testing and a review of your diabetes history. Then your eye doctor places drops in both eyes to widen (dilate) your pupils, giving them a much better view of the inside of your eye. These drops take roughly 20 to 30 minutes to work fully, and you’ll usually just sit in the waiting area during this time. Once your pupils are wide enough, the doctor examines the interior of your eyes, looking for irregularities like swollen blood vessels, leaking fluid, or new abnormal vessel growth.
In many cases, your doctor will also perform optical coherence tomography, commonly called OCT. This imaging test creates detailed cross-sectional pictures of your retina and measures its thickness, which reveals whether fluid has leaked into the retinal tissue. The scan itself takes only a few minutes and is painless. If your doctor suspects more advanced problems, they may order fluorescein angiography, where a dye is injected into a vein in your arm and photographs are taken as it travels through the blood vessels in your eyes. This additional test can add 15 to 30 minutes to your visit.
Newer Imaging Options That Skip Dilation
Some clinics now use high-resolution retinal cameras that can photograph the back of your eye without dilating drops. These non-dilated retinal images take about 2 minutes to capture. The trade-off is that they don’t always provide as complete a view as a fully dilated exam, so your doctor may still recommend dilation if the images are unclear or if there are signs of a problem. For routine annual screening in someone with no prior retinopathy, though, these faster imaging methods are increasingly common and can significantly cut down your total appointment time.
How Long the Blurry Vision Lasts
The exam itself may be done in under an hour, but the aftereffects of dilation stick around longer. Your near vision will be blurry for several hours afterward, and your eyes will be noticeably sensitive to light. Bring sunglasses to your appointment, even on a cloudy day, because the walk to your car can be uncomfortable with fully dilated pupils.
There are no formal medical guidelines prohibiting driving after dilation, but it’s a good idea to arrange a ride if possible. If driving is your only option, give yourself time to adjust, stick to familiar roads, and avoid driving in bright sunlight. Many people find that their vision returns to normal within 4 to 6 hours, though some people with lighter-colored eyes may stay dilated a bit longer.
When You’ll Get Results
For the basic dilated exam, your doctor can often share preliminary findings the same day. They can see the retina in real time and will tell you whether there are visible signs of diabetic eye disease. OCT results are also typically available immediately, since the images appear on a screen during the scan. If fluorescein angiography is performed, interpreting those images may take a bit longer, but results are still usually discussed at the same visit or within a few days.
How Often You’ll Need One
The frequency depends on your type of diabetes and what previous exams have shown. If you have type 2 diabetes, the American Diabetes Association recommends a comprehensive dilated eye exam at the time of diagnosis, since type 2 can go undetected for years and retinal damage may already be present. For type 1 diabetes, the first exam should happen within 5 years of diagnosis.
After that initial exam, the schedule depends on your results. If there’s no sign of retinopathy and your blood sugar is well controlled, screening every 1 to 2 years is generally sufficient. If any level of diabetic retinopathy is found, you’ll need annual exams at minimum. Progressing or sight-threatening retinopathy calls for even more frequent monitoring, sometimes every few months.
How to Plan Your Day
Block out about two hours total: one hour for the appointment itself and another hour for the dilation effects to ease up enough that you’re comfortable. Schedule your exam for a time when you won’t need to read fine print, work on a computer, or drive long distances immediately afterward. Morning appointments work well for many people, since the dilation tends to wear off by the afternoon. If you’re having a first-time diabetic eye exam or your doctor has ordered additional imaging beyond the standard screening, allow a little extra time.