# Diabetes and your eyes: how to protect your sight > Diabetes can damage the small blood vessels at the back of the eye, a condition called diabetic retinopathy. It causes no symptoms at first, and it is a leading cause of blindness in working-age adults. Most of that sight loss can be prevented with a yearly diabetic eye check and good control of blood sugar and blood pressure. Source: https://seebetter.co.za/blog/diabetes-and-your-eyes/ Publisher: See Better (https://seebetter.co.za/) Section: Eye conditions Published: 2026-10-11 Last updated: 2026-10-11 ## Key points - Diabetic eye damage is painless and symptom-free in the early stages. - Everyone with diabetes needs the back of their eyes examined at least once a year. - Good control of blood sugar, blood pressure and cholesterol slows the damage. - Blurred vision that comes and goes can be a sign of changing blood sugar. ## How diabetes affects the eyes The retina is the light-sensitive layer at the back of the eye. It is fed by a network of very fine blood vessels. Over the years, high blood sugar weakens the walls of these vessels. They bulge, leak fluid and blood, or close off. This is diabetic retinopathy. It usually progresses in stages: 1. **Early (background) retinopathy.** There are small bulges and leaks. Vision is normal and you feel nothing. 2. **Macular oedema.** Fluid leaks into the macula, the centre of the retina. Central vision becomes blurred. This can happen at any stage. 3. **Advanced (proliferative) retinopathy.** Starved of oxygen, the retina grows fragile new vessels that bleed easily and can cause scarring, retinal detachment and severe loss of sight. Millions of South Africans live with diabetes, and many do not know they have it. Sometimes an eye test gives the first clue. ## Symptoms, and why you cannot rely on them In the early stages there are none. That is the danger. By the time retinopathy causes symptoms, it is usually advanced. Later signs include: - blurred or patchy vision - vision that changes from day to day - dark spots, strings or floaters - difficulty seeing at night - colours that look washed out - sudden loss of vision > Sudden loss of vision, a sudden shower of floaters or a dark curtain across your sight is an emergency. See a doctor the same day. ## Other ways diabetes affects the eyes - **A fluctuating prescription.** High blood sugar makes the lens of the eye swell and vision blur. It can take weeks to settle once sugar levels come down. Glasses prescribed while your sugar is unstable may be wrong a month later. - **Cataracts.** People with diabetes tend to develop [cataracts](https://seebetter.co.za/blog/cataract-symptoms/) earlier. - **Glaucoma.** Diabetes raises the risk of [glaucoma](https://seebetter.co.za/blog/glaucoma-symptoms-and-testing/). - **Dry eyes** and slower healing of the surface of the eye. ## The yearly diabetic eye check Everyone with diabetes should have the back of their eyes examined at least once a year. The examination is done with the pupils widened by drops, with retinal photographs, or both. - **Type 2 diabetes:** start at diagnosis, because it may have been present for years. - **Type 1 diabetes:** start within five years of diagnosis, then yearly. - **Pregnancy with diabetes:** your eyes need extra checks, because retinopathy can progress faster during pregnancy. A routine test for glasses is not automatically the same thing as a diabetic retinal check. Tell your optometrist that you have diabetes every time, so that they examine the back of your eyes closely or refer you for retinal screening. If retinopathy is found, you will be referred to an ophthalmologist. ## How to protect your sight - **Control your blood sugar.** Keeping your HbA1c close to the target agreed with your doctor is the single biggest factor. - **Control your blood pressure and cholesterol.** Both damage the same small vessels. - **Do not smoke.** - **Take your medication as prescribed** and keep your clinic or doctor's appointments. - **Stay active and eat well.** See [the best foods for eye health](https://seebetter.co.za/blog/best-foods-for-eye-health/). - **Never skip the yearly eye check,** even when you see perfectly. - **Report any change in your vision promptly.** ## How diabetic eye disease is treated Treatment is provided by an ophthalmologist and works best before sight is lost. - **Injections into the eye** of medicine that reduces leaking and stops abnormal vessels from growing. The eye is numbed first. - **Laser treatment** to seal leaking vessels or shrink abnormal ones. - **Surgery** (vitrectomy) for bleeding into the eye or a detached retina. These treatments are good at preventing further loss. They are much less able to restore sight that has already gone, which is why early detection is everything. ## Getting your glasses right Have your eyes tested for glasses when your blood sugar has been stable for a few weeks, and tell the optometrist your recent readings. If your vision swings during the day, mention that too. See Better tests eyes at home across Gauteng for R450, which makes it easier to keep up with regular checks. Let us know that you have diabetes when you book. If the optometrist sees anything that needs a specialist, you will be referred. ## Frequently asked questions ### How often should a person with diabetes have an eye test? At least once a year, and more often if your doctor or optometrist advises it, for example if retinopathy has been found or you are pregnant. ### Can diabetic retinopathy be reversed? Early changes can stabilise, and sometimes improve, with good control of blood sugar and blood pressure. Advanced damage cannot be undone, but treatment can stop it getting worse. ### Why is my vision blurry when my sugar is high? High blood sugar draws fluid into the lens of the eye and changes its shape, which shifts your focus. The blur usually clears once your sugar has been back in range for a few weeks. ### Can diabetes make you blind? It can, if retinopathy is not found and treated. With yearly eye checks and good control of blood sugar and blood pressure, most severe sight loss from diabetes can be prevented. ## About See Better See Better is a mobile optometry practice in Gauteng, South Africa. A qualified, HPCSA-registered optometrist travels to the client's home, workplace, school or event, so there is no practice to visit. - Areas served: Johannesburg, Pretoria (Tshwane), Ekurhuleni (East Rand), the West Rand and the Vaal. - Eye test at home: R450 (cash price). - Eye test + frame + single vision lenses + tint: R1199 (cash price). - Eye test + frame + bifocal lenses + tint: R1699 (cash price). - Eye test + frame + multifocal lenses + tint: R2099 (cash price). - All glasses carry a 1-year warranty. - We are registered with most medical aids and charge at medical aid tariffs. - Book on WhatsApp: +27 66 181 8667 (https://wa.me/27661818667) - Email: info@seebetter.co.za - Website: https://seebetter.co.za/