What causes floaters?
Floaters are those tiny spots or 'cobwebs' that drift around in your field of vision. They occur behind the lens and in front of the retina, and tend to appear when tiny pieces of vitreous humour – the jelly-like substance that fills the middle of the eyeball – break loose. Floaters are very common, particularly among the over-60s.
'Floaters can be something or nothing,' says Francesca Marchetti, a leading optometrist and adviser to independent eye-care panel WINK. 'Over time, they tend to disperse. Because they become part of our daily vision, the brain tends to learn to ignore them.'
When should I worry? 'A sudden onset of floaters, especially if accompanied by flashing lights, could be a sign of a retinal tear or detachment,' says Marchetti. 'These are both sight-threatening conditions, so do make an urgent appointment to see your optometrist.'
Posterior vitreous detachment (PVD), caused by changes to the vitreous humour, is a common – and normally harmless – condition that affects around half of us by the time we reach 50. But in a few cases, the vitreous humour tears the retina as it pulls away. Left untreated, these tears can cause retinal detachment, which is when the retina separates completely from the wall at the back of the eye, potentially causing permanent damage.
Any other causes? Floaters are more common in people with diabetes or short-sightedness. Cataract surgery can also increase risk, as can an eye infection or injury.
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What causes blurring?
Blurred vision is a loss of sharpness, making everything seem out-of-focus. 'It can happen for a plethora of reasons – the most likely being that you just need to update your spectacle or contact lens prescription,' says Marchetti.
When should I worry? 'Blurring should never be ignored,' warns Marchetti. 'It can also be an indication of a serious problem inside the eye, such as retinal detachment.' Like floaters, blurring can be a symptom of diabetic retinopathy – a complication of diabetes, caused by high blood sugar levels damaging the back of the eye.
Blurred vision is sometimes confused with cloudy vision, which is when objects appear 'milky'. Cloudy vision is a symptom of cataracts – so again, it's important to get checked out by an optometrist as soon as possible.
Any other causes? Blurring is a common symptom of digital eye strain – so do remember to take regular screen breaks. It can also indicate chronic dry eye syndrome or the onset of a migraine, and may occur as a temporary reaction to laser eye surgery or certain eye drops or medication. If you have any concerns at all, consult your GP or optometrist.
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What causes twitching?
Eye twitching is fairly common, and usually affects just the lower eyelid of one eye. 'It's normally nothing to worry about and can simply be put down to tiredness,' says Marchetti. 'It will come on suddenly and go away as quickly as it appeared.'
When should I worry? 'If the twitching persists for any length of time, it's important to see your optometrist or GP so you can identify the underlying cause,' advises Marchetti.
As well as tiredness, twitching may be a reaction to long-term stress, which needs to be addressed as soon as possible. And again, it could be caused by sight problems that can be solved with a new spectacles or lens prescription, or by digital eye strain.
Repeated twitching – or excessive blinking – may, in rare cases, be caused by a condition called blepharospasm, which is triggered by bright lights, stress or tiredness. Severe cases can be treated with Botox injections to relax the muscles controlling the eyelids.
Any other causes? Consuming too much alcohol or caffeine may also lead to eye twitches – as can nutritional imbalances. 'It's important to look after your eyes by having regular eye examinations and eating a healthy, balanced, vitamin-rich diet,' says Marchetti.
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