# How to Keep Your Eyes Healthy | World Aid Network > Source: https://worldaidnetwork.org/blog/how-to-keep-eyes-healthy > The WHO estimates 80% of visual impairment is avoidable. Learn the NHS-backed steps for healthy eyes: eye tests, UV protection, diet and warning signs. Direct Answer The most important steps for eye health are regular eye tests at least every two years, not smoking, wearing UV400-rated sunglasses, eating leafy greens and oily fish, and managing diabetes and blood pressure. The World Health Organization estimates roughly 80% of visual impairment worldwide is avoidable. World Aid Network funds eye surgery for poor patients. Sight is consistently rated the sense people fear losing most. Yet many of the conditions that cause blindness and visual impairment — including cataracts, glaucoma, diabetic retinopathy and age-related macular degeneration — can be prevented, significantly delayed or caught early enough to treat, through simple lifestyle measures and regular eye care. The World Health Organization estimates that approximately 80% of visual impairment worldwide is avoidable — meaning it could have been prevented or treated. In the UK, the NHS provides free eye tests for those at risk, and opticians can detect a wide range of eye conditions — and even systemic diseases such as diabetes and high blood pressure — during a routine examination. This guide answers the twenty most commonly searched questions about how to look after your eyes, drawing on NHS and WHO guidance. ## What is the most important things you can do for your eye health? The NHS identifies the following as the most important steps: attend regular eye tests (at least every two years, more frequently if recommended); do not smoke — smoking significantly increases the risk of macular degeneration, cataracts and optic nerve damage; wear UV-protective sunglasses (UV400 rated, CE marked) in bright sunlight; eat a varied diet rich in leafy green vegetables, oily fish and colourful fruit; maintain a healthy weight and manage diabetes and blood pressure well; protect your eyes from injury at work and during sport. Many serious eye conditions — including glaucoma and age-related macular degeneration — develop without symptoms in their early stages. A routine eye examination is the only reliable way to detect them before significant, irreversible damage has occurred. The NHS provides free eye tests for people over 60, those with a family history of glaucoma (from age 40), people of black African or Caribbean heritage (from age 40), and others at elevated risk. ## What are diet and nutrition for eye health? A nutritious diet supports eye health by providing the antioxidants, vitamins and minerals that protect retinal cells from oxidative damage. The nutrients with the strongest evidence for eye health include: lutein and zeaxanthin — found in leafy greens (kale, spinach, broccoli) and eggs — which concentrate in the macula and protect against age-related macular degeneration and cataracts; omega-3 fatty acids (oily fish: salmon, sardines, mackerel) — associated with reduced AMD risk and dry eye symptom improvement; vitamin A (orange and yellow vegetables, dairy) — essential for the rod photoreceptors used in dim-light vision; and vitamins C and E plus zinc, which contribute to the antioxidant defence of retinal tissue. Large clinical trials (the AREDS and AREDS2 studies) demonstrated that specific high-dose antioxidant and zinc supplements reduce the risk of progression from intermediate to advanced AMD by approximately 25–30% in people with existing intermediate AMD. These supplements — available over the counter as 'AREDS formula' preparations — are recommended by ophthalmologists for this specific group but are not proven to prevent AMD in people who do not yet have the condition. ## What are warning signs of serious eye conditions? Some eye symptoms require urgent or emergency assessment. Contact your GP, optician or A&E immediately if you experience: sudden loss of vision in one or both eyes; a sudden increase in floaters (dark spots or strings in your vision) especially with flashes of light — these can indicate retinal detachment, which is a surgical emergency; a curtain or shadow coming across your vision; sudden onset of a red, painful eye with blurred vision (possible acute angle-closure glaucoma); or eye pain associated with headache, nausea and vomiting. Non-urgent symptoms that should be assessed by your optician within a few weeks include: gradual worsening of vision not corrected by your current glasses; distortion or waviness of straight lines (a classic symptom of wet AMD); persistent double vision; or any new change in your vision that concerns you. ### Key takeaways - The most important steps for eye health are: regular eye tests (at least every two years), not smoking, wearing UV400-rated sunglasses, eating leafy greens and oily fish, and managing diabetes and blood pressure well. - Screen use does not cause permanent eye damage — but does cause digital eye strain. The 20-20-20 rule (every 20 minutes, look at something 20 feet away for 20 seconds) reduces eye fatigue. - Wear UV400/CE marked sunglasses. UV radiation contributes to cataract formation and macular degeneration. UV protection is cumulative — sun protection from childhood onwards matters. - Know the warning signs requiring urgent attention: sudden vision loss, sudden increase in floaters with flashes of light, a curtain across your vision, or a suddenly painful red eye. - The WHO estimates 80% of global visual impairment is avoidable. Sight charities including World Aid Network fund eye surgery and eye care for poor patients who would otherwise lose their sight unnecessarily. ## Frequently asked questions How often should I have an eye test? The NHS recommends a routine eye test at least every two years for most adults. Some people need more frequent tests — including those with diabetes (annual), people with glaucoma or at high risk of it (six-monthly or annual), children and young people, and those with high myopia (short-sightedness). Your optician will advise you on the recommended interval based on your eyes and risk factors. Eye tests detect more than just vision problems — they can also identify early signs of diabetes, hypertension, and brain tumours. What foods are good for eye health? The NHS advises a varied, balanced diet for eye health. Foods with the strongest evidence for supporting vision include: leafy green vegetables (kale, spinach, broccoli) and eggs — rich in lutein and zeaxanthin which protect the macula; oily fish (salmon, sardines, mackerel) — rich in omega-3 fatty acids linked to reduced AMD risk; orange and yellow vegetables (carrots, sweet potato, squash) — rich in beta-carotene, a precursor of vitamin A essential for dim-light vision; and citrus fruits, berries and nuts for vitamins C and E. Does smoking affect eyesight? Yes, significantly. Smoking is one of the biggest modifiable risk factors for sight loss. It approximately doubles the risk of age-related macular degeneration (AMD) — the most common cause of permanent vision loss in the UK — and is strongly associated with an increased risk of cataracts and optic nerve damage. Smoking restricts blood flow to the retina and introduces oxidative stress that damages photoreceptor cells. Stopping smoking at any age reduces the risk of smoking-related eye disease, and the NHS offers free smoking cessation support. How does diabetes affect eyesight? Diabetes causes diabetic retinopathy — damage to the small blood vessels in the retina caused by consistently high blood sugar. In early stages, blood vessels become leaky (background retinopathy). In advanced stages, new fragile blood vessels grow on the retina (proliferative retinopathy), which can bleed and cause sudden vision loss, vitreous haemorrhage or traction retinal detachment. Diabetic macular oedema — fluid accumulation in the macula — is the most common cause of diabetes-related vision loss. Diabetic retinopathy is the leading cause of blindness in working-age adults in the UK. All people with diabetes should attend their annual NHS diabetic eye screening. What vitamins are good for eye health? Key vitamins and minerals for eye health include: vitamin A (essential for the photopigment rhodopsin in rod cells; deficiency causes night blindness — the most common preventable cause of childhood blindness globally); vitamin C (antioxidant protective of the lens — reduced levels linked to cataract); vitamin E (antioxidant protective of retinal cell membranes); zinc (required for vitamin A metabolism and protective of macular cells); and lutein and zeaxanthin (carotenoids that filter harmful blue light and protect macular cells from oxidative damage). AREDS2 supplements are recommended by ophthalmologists for patients with intermediate AMD. Does blue light from screens damage eyesight? Current NHS and WHO guidance states that normal use of digital screens does not cause permanent damage to the eyes. The amount of blue light emitted by smartphone, computer and tablet screens is far below the level shown to cause retinal harm in laboratory studies. Screen use does cause digital eye strain (tired, dry, sore eyes and temporary blurring) due to reduced blinking and sustained near-focus. Blue-light-blocking glasses are not recommended by opticians as a way to prevent eye disease — their benefit is unproven. Good screen habits — regular breaks and correct screen distance — are the effective solution. What is the 20-20-20 rule? The 20-20-20 rule is an NHS-recommended strategy to reduce digital eye strain during prolonged screen use: every 20 minutes, look at something at least 20 feet (6 metres) away for at least 20 seconds. This gives the ciliary muscles inside the eye — which contract to focus on near objects — a brief rest, reducing fatigue. Additional measures include adjusting screen brightness to match your surroundings, positioning the screen slightly below eye level, ensuring good lighting, and using lubricating eye drops if your eyes feel dry. What sunglasses protect eyes from UV radiation? The NHS advises choosing sunglasses labelled 'UV400' — meaning they block 99–100% of UV radiation — and carrying the CE mark, confirming they meet European safety standards. The category of lens darkness does not indicate UV protection; cheap sunglasses with dark lenses but no UV coating can be worse than no glasses, as dilated pupils admit more UV. Wraparound styles provide better peripheral protection. UV protection matters year-round — UV radiation reflects off snow, water and sand — and from early childhood, as UV damage to the lens is cumulative. How can I protect my eyes at work? Appropriate eye protection at work is both a legal requirement and essential to prevent injury. Safety spectacles, goggles, face shields or welding visors should be worn when working with: hazardous chemicals, dust or particles; power tools; welding or cutting equipment; lasers; or in environments with flying debris. Employers are legally required to provide suitable eye protection under the Personal Protective Equipment at Work Regulations. Those who work at screens all day are entitled to an employer-funded eye test and, if needed, basic spectacles for screen use. Can high blood pressure affect eyesight? Yes. Chronic high blood pressure (hypertension) damages the blood vessels of the retina, causing hypertensive retinopathy — changes including vessel narrowing, haemorrhages, exudates and, in severe cases, optic disc swelling (papilloedema). Very severe acute hypertension (hypertensive emergency) can cause sudden visual loss. High blood pressure also contributes to the risk of central retinal vein or artery occlusion — a stroke equivalent affecting the eye — which can cause sudden, severe vision loss. Your optician can detect hypertensive changes to retinal blood vessels during a routine eye examination. What are the early signs of eye problems? Changes that warrant a prompt optician appointment include: gradual blurring of distance or near vision not corrected by your current glasses; increased glare from lights; halos around lights; difficulty seeing in dim conditions; distortion of straight lines; colour vision changes; and persistent or increasing eye strain or headaches. Many serious conditions — including glaucoma — produce no early symptoms, which is why regular eye tests are essential even when your vision feels normal. What are the warning signs that need urgent attention? The following symptoms require urgent or emergency eye assessment: sudden loss of vision in one or both eyes; a sudden large increase in floaters, especially accompanied by flashes of light (possible retinal detachment — a surgical emergency); a curtain or shadow coming across your visual field; sudden onset of a red, painful eye with blurred vision and nausea (possible acute angle-closure glaucoma); sudden double vision; or eye pain with severe headache. If you experience any of these, go to A&E or your nearest eye casualty department immediately. How can I prevent macular degeneration? Age-related macular degeneration (AMD) cannot be entirely prevented, but several modifiable factors reduce risk. The NHS advises: stopping smoking (doubles AMD risk); eating a diet rich in leafy greens, oily fish and colourful vegetables (sources of lutein, zeaxanthin, omega-3 and antioxidants); wearing UV-protective sunglasses; maintaining a healthy weight; and attending regular eye tests for early detection. AREDS2 antioxidant supplements are recommended by ophthalmologists to slow progression in people already diagnosed with intermediate AMD. Does rubbing your eyes cause damage? Frequent and vigorous eye rubbing is associated with two main risks. First, in people with keratoconus (a condition in which the cornea becomes progressively thinner and cone-shaped), habitual eye rubbing appears to accelerate progression and is strongly advised against. Second, rubbing can transfer bacteria from hands to the eye, increasing the risk of infection. The urge to rub itchy eyes is often caused by allergic conjunctivitis; antihistamine eye drops, cold compresses and avoiding allergens are more effective approaches than rubbing. How should I care for contact lenses? Contact lens hygiene is important to prevent infections, including Acanthamoeba keratitis — a rare but serious infection that can cause permanent corneal scarring and vision loss. The NHS advises: always wash and dry hands thoroughly before handling lenses; never sleep in daily lenses unless specifically prescribed for overnight wear; never use tap water to clean or store lenses or lens cases; never swim in lenses; replace the lens case regularly (at least monthly); and remove lenses immediately if your eye becomes red, painful or your vision changes. Annual optician check-ups are required for contact lens prescriptions. What is dry eye syndrome? Dry eye syndrome (dry eye disease) occurs when the eyes do not produce enough tears or when tears evaporate too quickly, leaving the ocular surface inadequately lubricated. Symptoms include: grittiness, burning, stinging, redness, intermittent blurred vision and, paradoxically, watering eyes (reflex tearing in response to dryness). Risk factors include prolonged screen use, contact lens wear, air-conditioned environments, ageing, menopause, certain medications (antihistamines, antidepressants, beta-blockers) and autoimmune conditions such as Sjögren's syndrome. Treatment includes preservative-free lubricating eye drops, eyelid hygiene, heated eye masks and, in more severe cases, prescription medications. Can sleep deprivation affect eyesight? Insufficient sleep can cause temporary eye symptoms including eye twitching (myokymia), eye strain, light sensitivity, blurred vision, dry eyes and difficulty focusing. These are caused by eye muscle fatigue and insufficient tear production during waking hours. Serious, permanent vision damage from sleep deprivation alone is not documented in clinical literature. However, some conditions worsened by sleep deprivation — such as dry eye disease and certain types of headache — can affect vision indirectly. Most eye symptoms caused by poor sleep resolve with adequate rest. Are there eye exercises to improve vision? There is no reliable clinical evidence that eye exercises improve refractive errors such as short-sightedness, long-sightedness or astigmatism — these require glasses, contact lenses or laser eye surgery. Eye exercises are used therapeutically by orthoptists for convergence insufficiency (difficulty coordinating the eyes for near work) and certain types of lazy eye (amblyopia). The 20-20-20 rule is a helpful practice for reducing eye strain rather than improving optical correction. Claims that exercises can correct refractive error or cure eye disease are not supported by the NHS or WHO. What should I do if I get something in my eye? For a small particle such as dust or an eyelash: do not rub the eye; try blinking repeatedly to flush it out; rinse the eye with clean water or sterile saline. For a chemical splash: immediately flush the eye with large amounts of clean water for at least 15–20 minutes, holding the eyelid open; call 999 or go to A&E urgently. For a penetrating injury (something embedded in the eye): do not try to remove it; cover the eye loosely (do not apply pressure) and go to A&E immediately. Never rub an eye when a penetrating injury is suspected. How does access to eye care differ around the world? The WHO estimates that 80% of global visual impairment is avoidable — meaning it could have been prevented or treated with available interventions. In the UK, NHS eye tests are free for many groups, cataracts are treated routinely, glaucoma is managed with affordable drops and laser, and diabetic eye screening is offered annually to all people with diabetes. In low-income countries, there is a severe shortage of ophthalmologists — often fewer than one per million people in the poorest regions — and essential treatments are unaffordable to the rural poor. World Aid Network funds sight-restoring eye surgery and eye care for poor patients through locally-licensed ophthalmologists. [**Medically reviewed by Mr Mohamed Mohyudin**MBChB BSc MSc FRCOphth CCT · GMC No. 7039600 · Consultant Ophthalmic Surgeon](https://mohamedmohyudin.co.uk/) This article was reviewed by the World Aid Network editorial team for factual accuracy against WHO, NHS, HMRC and Charity Commission sources. World Aid Network is a UK Charitable Incorporated Organisation (charity registration in progress), governed by named trustees. ### Help give the gift of sight to those who cannot afford eye care The WHO estimates 80% of global blindness is avoidable. In the UK, eye care is accessible and often free. In low-income countries, millions lose their sight needlessly because basic eye surgery and treatment are out of reach. World Aid Network funds sight-restoring surgery through locally-licensed ophthalmologists. Your donation restores independence, livelihood and dignity. [Donate Now](/donate)[View the Gift of Sight Appeal](/appeal/gift-of-sight)[Eye charity programmes](/blindness-charity) Charitable Incorporated Organisation Funds restricted to our charitable Objects Gift Aid will apply for UK taxpayers once registration is complete --- World Aid Network is a UK Charitable Incorporated Organisation (charity registration in progress; application ref 5290505, ICO ref ZC156579).