When we're looking at an image and it loses some of its sharpness and definition, this is known as blurred vision. It becomes harder to make out the details and the image may look fuzzy. This can affect just one eye, or both eyes at the same time.
Blurred vision – when we can't make out the fine details of an image – is different from cloudy vision (when objects seem to be obscured or "milky" looking), and from double vision (when we see two images of a single object).
Blurred vision that's temporary and occasional is often just a sign that our eyes are tired. However, blurred vision that persists, comes on suddenly, or occurs alongside other medical conditions, can be a symptom of a more serious problem that needs attention.
When to seek help immediately
You should go to A&E immediately if you have blurred vision that comes on very suddenly, and you also experience any of the following:
- Intense eye pain
- Nausea or vomiting
- A headache
- You can see 'rings' around lights
- You can see 'flashing lights'
- Your eye is red
- The area around your eye is tender
- You suddenly lose some or all of your vision
Blurred vision & tiredness
If you've been working hard and your eyesight becomes blurry towards the end of the day, your eyes may simply be tired and strained. You may notice this more if you've been working with screens or doing a lot of reading. Take a break from working or looking at screens and give yourself and your eyes a rest.
If your blurred vision clears up after resting, and if you only experience it occasionally, it's most likely nothing to worry about. However, if it's causing you concern, make an appointment to see your optician. They will check the health of your eyes and will be able to spot any potential problems.
Blurred vision that persists
If you have ongoing or regular blurring to your vision, you should see your optician as soon as possible. Don't wait for your next scheduled eye check to have the problem looked at.
Your optician will check the health of your eyes to see if there are any signs of an eye condition developing. They will also use an eye test chart to check how your eyesight is performing and find out if you may need some type of vision correction.
Blurred vision & glaucoma
Glaucoma is a condition where fluid builds up in the front part of the eye. This puts pressure on the optic nerve. If it's not treated, it can cause damage and affect your sight.
Glaucoma often doesn't cause symptoms in its early stages, which is why it's important to have regular eye checks even if your vision seems fine. Your optician can spot the early signs of glaucoma and will make sure you receive treatment to help stop it from progressing.
Blurred vision & age-related macular degeneration (AMD)
Blurring to the central part of your vision can be a sign of a condition called age-related macular degeneration. Other symptoms of macular degeneration to be aware of include:
- Blind spots
- Visual distortions, such as straight lines looking crooked or wavy
- Colours seeming less vibrant
- Needing a brighter light than usual to read
If you're experiencing blurring to the central part of your vision, or any of the other symptoms described above, make an appointment with your optician straight away.
Don't put it off until your next scheduled eye test.
Blurred vision & pre-eclampsia
Pre-eclampsia is a condition that affects some pregnant women. It can occur at any time during your pregnancy, but it most commonly appears in the second half of pregnancy (after the 20th week). Your midwife will check you for early signs of pre-eclampsia at your regular antenatal appointments by checking your urine and blood pressure.
Blurred vision in pregnancy can be a sign that you are developing pre-eclampsia. Other signs of pre-eclampsia to be aware of include:
- Sudden swelling of your face, hands, ankles and feet
- Severe headache
- Pain just below your ribs
If you're pregnant and you experience blurred vision, or any other symptom of pre-eclampsia, you should call your Doctor or midwife immediately for an urgent appointment. Don't wait for your next routine visit.
Blurred vision & diabetes
If you have diabetes, your vision may fluctuate especially if your blood sugar is not well controlled, and you may be at risk of developing a complication known as diabetic retinopathy. This happens when high blood sugar levels cause damage to the tiny arteries at the back of your eye (the retina).
If it's left untreated, diabetic retinopathy can ultimately cause blindness. However, your optician can usually spot the early signs of diabetic retinopathy before any major damage is caused. For this reason, if you have diabetes, it's very important you have your eyes examined regularly.
One symptom of diabetic retinopathy that's starting to cause damage to your eyes is blurry vision. Other symptoms to be aware of include:
- Gradually worsening vision
- Sudden vision loss
- Shapes or 'floaters' in your field of vision
- Patchy vision
- Eye pain or redness
If you have diabetes and you experience blurry vision, or any other symptom mentioned above, you should see your optician urgently. Don't wait for your next screening appointment.
- If you have occasional blurred vision at the end of a long day, it's unlikely to be anything serious. However, if you're worried, make an appointment with your optician
- If you're pregnant and you experience blurred vision, you should see your Doctor or midwife as soon as you can – don't wait for your next scheduled appointment
- If you experience persistent blurred vision, make an appointment to see your optician as soon as possible