Did you know that people with diabetes are more likely to go blind than those without?
As eye specialists committed to trust, clarity, and expertise, our mission here is to break down what diabetes does to the eyes. We want to highlight warning signs to watch for, and make the case for why regular eye tests aren’t optional, they’re essential for preventing vision loss.
What is diabetic retinopathy?
The most prevalent diabetes-related eye complication is diabetic retinopathy (DR). This is damage to the retina’s tiny blood vessels caused by chronic high blood sugar. Over time, these weakened vessels leak fluid or haemorrhage, causing swelling, scar tissue, and even new abnormal blood vessel growth. Without treatment, DR can progress to permanent vision loss or blindness. Globally, around one-third of individuals with diabetes have some form of DR.
How diabetes affects the eyes
The longer someone lives with diabetes, especially with poor glucose control, the higher the risk of diabetic retinopathy (DR). This is because prolonged exposure to high blood sugar damages the tiny blood vessels in the retina, weakening their walls and leading to leakage, blockages, or abnormal vessel growth.
Over time, this cumulative damage becomes harder to reverse. After five years, roughly 25% of people with type 1 diabetes show signs of retinopathy. By 10 to 15 years, that figure rises to 60–80%, reflecting the progressive nature of the disease when glucose levels aren’t tightly managed.
High blood pressure and uncontrolled cholesterol further exacerbate this damage by increasing stress on already fragile blood vessels. These additional cardiovascular risk factors speed up the deterioration of retinal health. In people with type 2 diabetes, retinopathy is often present at the time of diagnosis because the condition may have developed silently over several years.
This highlights why early detection, regular screening, and consistent control of blood sugar and overall health are absolutely critical to preventing vision loss.
Symptoms of diabetic retinopathy to watch for
One of the most dangerous aspects of diabetic retinopathy is how silently it develops. In its early stages, DR is often completely asymptomatic, meaning you may not notice any changes to your vision. That’s why routine dilated eye exams are critical, even if your sight seems fine.
As the condition progresses, symptoms begin to appear. These signs can be subtle at first but may worsen rapidly if left untreated:
1. Blurry or distorted vision
This is often one of the first noticeable symptoms. It may affect your central vision, making it harder to read, drive, or recognise faces. Blurring can come and go or progressively worsen over time.
Possible cause: Fluid leakage from damaged retinal vessels or swelling in the macula, known as diabetic macular edema.
2. Floaters
These appear as dark specks, strings, or cobweb-like shapes that drift across your visual field. While floaters can be harmless and age-related, in diabetic patients they may signal something more serious.
Possible cause: Tiny specks of blood leaking into the vitreous (the gel-like substance inside your eye), especially in more advanced or proliferative diabetic retinopathy.
3. Dark or empty spots in your vision
You may notice “blind spots” or areas of vision that seem dim or completely absent. This can significantly affect your ability to see details, especially in low-light conditions.
Possible cause: Retinal ischemia (reduced blood flow to parts of the retina), or scarring that disrupts normal vision.
4. Difficulty perceiving colours
Colours may appear faded, muted, or washed out. This is less common than other symptoms but can still impact daily life, especially tasks requiring color discrimination like cooking, matching clothes, or reading warning labels.
Possible cause: Damage to the macula, the part of the retina responsible for sharp central vision and colour processing.
5. Sudden or total vision loss
A sudden and dramatic loss of vision is a medical emergency. It may happen in one or both eyes and typically results from vitreous haemorrhage (significant bleeding inside the eye) or retinal detachment.
Possible cause: Advanced PDR where abnormal new blood vessels rupture, or scar tissue pulls on the retina, causing it to detach.
Why regular eye tests are important
Up to 90% of vision loss from diabetes is avoidable with early detection and intervention. Modern treatments such as laser therapy, anti‑VEGF injections, tighter systemic control of glucose, blood pressure, and lipids, can halt or reverse damage in its early stages.
During an eye test, your optician performs a comprehensive dilated eye exam, using drops to widen your pupils. This allows a clear view of the retina, optic nerve, and blood vessels. Tools may include slit lamps, fundus examination, OCT scans, or fluorescein angiography to assess fluid leakage and retinal integrity.
This allows opticians to closely examine the inside of your eye, assess your overall eye health, and offer informed guidance or treatment if needed.
Risks and contributing factors to monitor
| Risk factor | How it affects eye health |
| Poor blood sugar control | Damages retinal micro-vessels; accelerates DR |
| High blood pressure/cholesterol | Raises risk of vessel leakage and ischemia |
| Duration of diabetes | Longer duration = higher risk of advanced DR |
| Smoking | Increases oxidative stress, vascular damage |
| Pregnancy | May accelerate DR progression |
| Lack of screening/access | Delays diagnosis until vision-threatening stage |
Book an eye test at London’s best opticians
When it comes to protecting your vision, don’t settle for anything less than expert care. At our London Therapeutic Optometry clinic, you’ll be seen by highly experienced optometrists and ophthalmologists who specialise in diabetic eye health.
We use state-of-the-art diagnostic technology, including digital retinal imaging and OCT scans, to detect even the earliest signs of diabetic retinopathy and other vision-threatening conditions.
Our personalised approach means you get more than just a prescription; you get a full picture of your eye health, clear guidance, and ongoing support. Book your comprehensive eye exam today and experience the gold standard in diabetic eye care.
