Most of us take our vision for granted, until something starts to go wrong. Your eyes can often give you subtle (or not-so-subtle) warnings that something’s not right. Knowing when to see an eye specialist and when to head straight to A&E, can protect your sight and even your life.
250 people in the UK begin to lose their sight every day, that’s one person every six minutes? With more than 2 million people already living with sight loss in the UK, staying vigilant about eye health is vital, especially when warning signs appear.
Here are the critical signs and symptoms you should never ignore.
1. Sudden blurriness or loss of vision
If your vision suddenly goes blurry in one or both eyes, don’t wait. This is especially urgent if it happens quickly and doesn’t improve after blinking or resting your eyes. Sudden blurriness can point to serious problems like:
- Retinal detachment
- Optic neuritis
- Stroke or transient ischemic attack (TIA)
- Acute glaucoma
In cases like these, an eye test isn’t enough. This is when you bypass the optician and go straight to A&E. Time is critical, especially with retinal or neurological conditions where early treatment can prevent permanent damage.
2. Flashes of light or floating spots
Flashes of light (like camera flashes) and floating specks in your vision can be signs of:
- Posterior vitreous detachment (common but often harmless)
- Retinal tear or retinal detachment (serious and urgent)
If you suddenly notice more floaters than usual, especially if they’re accompanied by flashing lights or a dark shadow across your vision, it could be a sign the retina is pulling away from the back of the eye. Contact an optometrist first before heading to A&E, majority of floaters are harmless but do need assessing, the friendly team and help gauge on how quickly you need to be seen
3. Eye pain or pressure
Discomfort in the eye isn’t always minor. Persistent or sharp eye pain could be linked to:
- Acute angle-closure glaucoma (a medical emergency)
- Eye infections (like uveitis or keratitis)
- Foreign bodies in the eye
- Corneal ulcers
If your eye hurts, especially if it comes with redness, light sensitivity, or blurred vision, don’t assume it’ll go away on its own. Acute glaucoma happens to approximately 2 cases per 100,000 people per year, making it rare but serious. Book an appointment with an eye specialist, or visit urgent care if symptoms escalate quickly.
4. Redness that doesn’t go away
Red eyes can be caused by tiredness, allergies, or dry eyes, but when redness lasts more than a day or two, especially if it’s only in one eye or is paired with discharge, pain, or blurry vision, it could be something serious.
Conditions that cause concerning eye redness include:
- Conjunctivitis (pink eye)
- Scleritis or episcleritis
- Uveitis
- Herpes simplex eye infections
A proper eye test won’t always catch these. You may need to see an eye specialist or an ophthalmologist for further investigation and treatment. At Safarian & Simon, we offer a dedicated dry eye and red eye clinic designed to diagnose and treat a wide range of ocular surface issues.
Whether you’re dealing with persistent irritation, redness, or stinging discomfort, our expert optometrists use cutting-edge diagnostics and advanced therapies. These include PL light therapy, Meibomian gland probing, and eyelid cleaning treatments like ZEST and Blephex. We use these to target the root causes and deliver long-lasting relief. Learn more about our dry eye and red eye services here.
5. Dry eyes that worsen over time
Dry eyes are common, affecting around a third of all adults, but don’t ignore them if they’re getting worse, causing discomfort, or affecting your vision. Severe dry eye can lead to:
- Corneal damage
- Infection
- Scarring
Can dry eyes cause blindness?
In extreme, untreated cases, yes. While rare, chronic dry eye can increase your risk of corneal ulcers or inflammation that can seriously impact vision. If artificial tears aren’t helping or you’re finding it hard to wear contact lenses, book an appointment with an eye specialist. Don’t just brush it off as an annoyance.
Learn more: Understanding Dry Eyes: Causes and Treatment Options
6. Double vision
Seeing double is not something to ignore. It could mean something simple like eye muscle strain, but it might also point to:
- Nerve damage
- Stroke
- Brain tumour
- Thyroid eye disease
If you suddenly start seeing two images instead of one, especially if it doesn’t go away when you cover one eye, seek immediate medical attention. This could be a red flag for a neurological or vascular issue and may require imaging scans and fast intervention.
7. Sudden sensitivity to light
Increased light sensitivity can be painful and disorienting. It might be linked to:
- Corneal abrasions
- Inflammation inside the eye (uveitis)
- Migraine aura
- Eye infections
If light is suddenly unbearable or comes with headaches, nausea, or visual changes, don’t delay. See a qualified eye doctor or visit urgent care depending on how intense the symptoms are.
8. Haloes around lights
Seeing rainbow-coloured rings or haloes around lights, especially at night, is a common symptom of acute glaucoma. This is one of the most time-sensitive eye emergencies. When pressure in the eye builds rapidly, it can cause permanent damage to the optic nerve.
Symptoms to watch for include:
- Eye pain
- Nausea
- Vomiting
- Sudden vision loss
This is absolutely an emergency. Do not wait for an optician’s appointment. Go straight to A&E.
9. Trouble seeing at night
Difficulty seeing in low light might be due to aging or a mild vision change. But if it’s worsening, it could also be a sign of:
- Cataracts
- Vitamin A deficiency
- Retinitis pigmentosa
- Diabetes-related retinal damage
These conditions need medical follow-up. An eye test can help track progression, but in some cases, you’ll need to be referred to an ophthalmologist for more advanced care.
10. Eye injury or trauma
Any blow to the eye, such as sports injury, accident, or foreign object, should be treated seriously. Even if it seems minor, injuries can cause:
- Internal bleeding in the eye
- Corneal scratches
- Retinal tears
- Orbital fractures
Get checked immediately. In most trauma cases, you’ll need to skip the optician and go directly to A&E or an emergency eye clinic.
When to see an expert optician vs. A&E: Contact Safarian & Simon expert ophthalmologist in London
Your eyes don’t have a backup. While many vision changes are harmless or manageable, others are signs of deeper, more dangerous problems. If something feels off, trust your gut.
Vision loss can happen quickly, and early treatment is often the only way to stop it. When in doubt, book an eye test.
Contact an optometrist first before heading to A&E, majority of floaters are harmless but do need assessing, the friendly team and help gauge on how quickly you need to be seen
We have the right experience and equipment to help detect diseases and rule out red flags concerns, we can also treatment many infections. Contact our team of specialists.
