Diabetes and your eyes: why yearly screening matters

If you live with diabetes, you'll know it involves a lot of checks. Eye checks are one of the easiest to put off, because your vision may seem perfectly fine. That's exactly why they matter.

How diabetes can affect the eyes

The most common diabetic eye disease is diabetic retinopathy, which affects the blood vessels in the retina at the back of the eye. The National Eye Institute says:

• Anyone with any kind of diabetes can get it, including type 1, type 2 and gestational diabetes.
• The risk goes up the longer someone has diabetes. Over time, more than half of people with diabetes develop it.
• People with diabetes are also at risk of other eye conditions, including cataract and glaucoma.

Why you can't rely on symptoms

The NEI says the early stages of diabetic retinopathy usually don't have any symptoms. Its educator's guide puts it plainly: diabetic retinopathy can damage your eyes even before you see changes in your vision.

The NEI also notes that some people notice changes such as trouble reading that come and go. In later stages, people may see dark floating spots or streaks that look like cobwebs. By the time symptoms appear, changes may already be under way, which is why regular checks are recommended even when vision feels normal.

How often to be checked

• In the US, the NEI says it's important to get a comprehensive dilated eye exam at least once a year if you have diabetes.
• In England, the NHS diabetic eye screening programme invites everyone with diabetes aged 12 or over. People whose last two screenings found no retinopathy are invited every 2 years, and others are screened more often.
• During pregnancy, the NEI says people with diabetes, or who develop gestational diabetes, are at high risk and should have a comprehensive dilated eye exam as soon as possible, then ask how often they'll need exams.

Follow the schedule your diabetes team or eye care professional sets for you. It may be different from the general guidance.

What screening involves

The NHS describes its diabetic eye screening test as usually taking about 30 minutes, with three parts:

• Reading letters on a chart
• Eye drops to widen the pupils
• Photographs of the back of the eyes

The drops can blur your vision and make you sensitive to light for a few hours. Bring sunglasses, and plan not to drive until your vision is back to normal.

What helps lower the risk

The NEI says managing your diabetes is the best way to lower your risk of diabetic retinopathy. That means keeping blood sugar in a healthy range, and it says controlling blood pressure and cholesterol can also help. The NEI guide adds that with early detection and timely treatment, diabetic eye disease can be controlled.

Your diabetes team is the right place to talk about your own targets. Screening doesn't replace that care. It works alongside it.

Preparing for your appointment

• Bring your glasses or contact lens details and a list of medicines.
• Note any vision changes, even ones that come and go, with the date and time.
• Mention if you're pregnant or planning a pregnancy.
• Ask when your next check is due, and put it in your calendar before you leave.

Our guide on what to tell your eye doctor has more ideas. Diabetic eye screening is separate from a routine sight test, so ask your optometrist whether you still need regular eye tests too. See how often to get your eyes checked.

When to see someone

Contact your eye care professional or diabetes team before your next scheduled check if:

• Your vision becomes blurry, or blurriness comes and goes
• You have trouble reading or seeing detail
• You notice new spots or streaks floating in your vision
• You've missed a screening appointment, so it can be rebooked