Common Eye Conditions

It’s easy to take your eyes for granted until they start to fail. Regular eye tests can detect common eye conditions, some of which can have serious consequences, long before they become a problem.

  • Short Sight (Myopia)

    Short sighted people struggle to see things at a distance, but have great near vision.  This happens when the eyeball is slightly longer than it needs to be for the eye to focus effectively, so the image is focused in front of the retina rather than on it.  Glasses or contact lenses move the image to the right position.  Short sight can develop at a very young age but commonly appears during our teens and twenties, when the eyeball is still growing and changing.

  • Long Sight (Hyperopia)

    Long-sighted people can usually see wonderfully well at a distance; often they can see quite well close up too but the muscles within the eye have to strain (accommodate) to achieve this.  Long-sight causes tiredness, headaches, and sometimes blurring of close vision if the muscles can’t cope.  Children can be very longsighted and still appear to be seeing well because they have such strong focussing muscles – it can be a struggle to convince them they need to wear glasses when they think they’re seeing perfectly well!  The Optometrist will take into account whether the degree of long sight is enough to cause strain or difficulties with learning when deciding whether someone is longsighted enough to need glasses.   

  • Astigmatism

    Astigmatism means the sight is less clear than it could be at all distances. It is basically a distortion in the eye’s focus caused by an irregular cornea or crystalline lens; often described as having ‘rugby ball’ shaped eyes rather than round ones.

    Most of us have a little bit of astigmatism but glasses or contact lenses help when there is enough to cause strain. You can have astigmatism with long-sight, short-sight or on its own!

  • Presbyopia

    Presbyopia is similar to long-sight in that it causes near vision to be hard work, but happens because the accommodating eye muscles start to lose their flexibility with age.  Presbyopia happens to us all; short-sighted people often don’t notice it because they have natural near focus anyway, but the rest of us notice we’re holding things further away and struggling to see small print around the age of 45.  Presbyopes start to need different prescriptions for different distances, so for many people varifocals are extremely helpful.  We’re full of ideas if you need something different but most people get on with new-generation varifocals very well! 

  • Floaters, shadows and flashing lights

    Floaters are usually caused by debris floating about in the vitreous jelly inside the eye – they’re especially common in short-sighted people but most of us develop a few later in life.  For the majority of people they’re annoying but harmless – however if you’ve suddenly noticed something new in your vision, we strongly recommend you get it checked urgently.  Most of us experience floaters at some point in our lives (see below) but in a small number of cases, new floaters or flashes in your vision can be a sign of more serious problems such as a retinal detachment.  The sooner it’s checked by an eye-care professional, the sooner you can relax – if we’re not available contact your nearest eye department for a same day appointment.

  • Cataracts

    As the eye ages the focusing lens inside becomes thicker, and eventually starts to become cloudy – this is known as a cataract. Cataract causes your vision to become more misty and less detailed and glare can be a problem, so often driving in difficult conditions can be unpleasant (such as facing oncoming headlights).

    Cataracts can be quite slow to progress so sometimes people don’t really notice the changes happening and their sense of colour can change quite dramatically; Monet’s paintings, for example, became much yellower in later years! Cataracts can be treated very successfully in most cases – in fact it is now the most commonly performed operation in the UK. Gone are the days of waiting for the cataract to become ‘ripe’ – modern keyhole surgical techniques allow the operation to be performed much earlier, so as soon as your vision starts to become adversely affected by cataract we can refer you to assess whether an operation may be beneficial.

    Most people who have had cataract surgery see well straight away and don’t even require stitches, just drops for a few weeks to help the eye settle. Although it happens to most of us, the onset of cataracts can be slowed using well-fitting good quality UV protective sunglasses, eating and exercising well, and not smoking. Certain medications and medical conditions can cause cataract to form more rapidly; we may monitor you more closely if we feel it is necessary.

  • AMD (Macular Degeneration)

    The macula is the central part of the retina. Although it is extremely small it is responsible for all detailed ‘direct line of sight’ vision, whereas the rest of the retina deals with peripheral ‘navigational’ vision. Wear and tear in the macular area is known as macular degeneration and can happen for a variety of reasons, but very often is a consequence of the eye ageing (age-related macular degeneration or AMD). Tasks such as reading and recognising features become increasingly more difficult with macular degeneration, to varying degrees.

    Most people with AMD have what is known as ‘dry AMD’, where the central retina gradually becomes damaged. Eating a diet rich in lutein-containing foods can help prevent the damage, as can using good quality UV eye protection to slow the ageing of the retina. Lutein is an antioxidant pigment found in certain foods and can be taken in supplement form.

    Smoking is known to increase the risk of getting AMD enormously, so we suggest you avoid it if you want to maintain good sight in later years! We are keen to monitor people with dry AMD as it can progress to the ‘wet’ form, where vision rapidly declines due to sudden changes in the blood vessels at the back of the eye. Caught early enough, wet AMD can be prevented, so it is vital that anyone noticing sudden blurring or distortion seeks professional attention immediately.OCT can help us monitor macular degeneration much more accurately than ever before.

  • Conjunctivitis

    There are many types of conjunctivitis: viral, bacterial and allergic are the most common types and can range from a mild pinkness and watering through to very puffy, sticky, bright red eyes!

    If you have red eyes that are not painful or light sensitive, and your vision is normal, the chances are it will clear up by itself in a few days. If you have any other symptoms at all or if it doesn’t clear within 5 days, it is very important that you seek a professional opinion from your Optometrist, as more serious & potentially sight-threatening conditions such as Iritis and corneal ulcers can look very similar.

    We don’t recommend using antibiotic eyedrops without consulting an eyecare professional first (they are ineffective for many red-eye conditions including a lot of cases of conjunctivitis). We are happy to offer advice but prefer to see you in person.

  • Glaucoma

    It is a sad fact that even today, there are people unknowingly losing their eyesight when in many cases this could be prevented by having regular Eye Examinations.

    Glaucoma is commonly the cause: because glaucoma is slow, progressive damage to the optic nerve, and usually has no symptoms, glaucoma patients often don’t realise they have a problem with their sight until about 50% of their useful field of vision has been irreversibly lost. Glaucoma is not always due to high pressure in the eyes but sometimes this is a factor. There is currently no way of predicting who will develop glaucoma, although we do know that a family history of the disease makes it more likely. Regular Eye Examinations can detect it in the very early stages and now OCT can help pick it up even earlier.

    The good news is that Glaucoma is preventable if caught early – it is usually treated by using drops to lower the pressure in the eye to protect the nerve.

    Very occasionally people experience what is known as ‘Closed Angle’ or ‘Acute’ Glaucoma. This is intensely painful and causes the eye to become very red, often causing blurred vision and ‘halos’ around lights. It is an emergency as sight loss can result very quickly if untreated, so if you suspect you may have it please attend the nearest hospital emergency department immediately.

 More eye conditions…


Where the two eyes do not focus well together because of a difference between them, for example one being much more long-sighted or short-sighted than the other. Anisometropia can be corrected with some spectacle lenses, although contact lenses are even better at balancing the images seen by the two eyes so they can work together properly.


Blepharitis is a very common problem and causes (sometimes microscopic) sticky or flaky deposits to build up in the eyelashes, irritating the eye surface and making you more prone to eye infections. It often goes hand-in-hand with Meibomian Gland Dysfunction: a blockage of the tiny oil glands along the edge of the eyelid. Simple bathing and cleansing treatments can help a lot, but it is important they are done regularly to keep the condition at bay. Blepharitis can feel very uncomfortable and similar to a dry eye, or sometimes gives no symptoms at all! With assessment we can fully advise on what preventative treatments may be suitable for you and work out whether it definitely is blepharitis you’re experiencing or whether there are other underlying issues.

Colour Vision & Colour Blind

Red/green colour vision deficiencies are the most common type of ‘colour-blindness’. To be completely colour-blind (monochromatic) is extremely rare and usually accompanies other vision and medical problems. Usually it is just a case of finding subtle shades of colour hard to distinguish, such as browns and purples. Testing colour vision can help us advise whether certain careers might be a problem (e.g. electricians and pilots). Interestingly, boys are much more likely to have a red/green colour deficiency than girls! If you suspect your perception of colours has changed this could be an indication of cataract or problems with the optic nerve, so it’s worth getting tested as soon as possible.

Diabetic Eye Disease & Retinopathy

There is, unfortunately, no such thing as ‘mild’ diabetes – all diabetics are at risk of eye complications. Diabetes can cause changes in the blood vessels at the back of the eye, leading to bleeds and fluid leakage which can go on to blur and distort sight if not kept in check. Good diabetic control is essential to keeping eyes healthy, and with regular eye examinations we can pick up these changes in the earliest stages and arrange for your GP to review your control, or arrange for hospital assessment and preventative treatment if necessary. Most diabetics do have an annual retinal screening examination, however we also monitor for any other changes in the eye (for example diabetic screening does not look for glaucoma) and signs of complications not found during the standard screening. As screening is usually carried out by taking a photograph of the central retina, we can pick up much more detail using our OCT scanner, so this is highly recommended for diabetics.

Double Vision (Diplopia)

Double vision can be caused by a cataract but is more commonly due to the eye muscles failing to work together properly. Some people wear corrective ‘prism’ lenses to help control double vision; these are slightly thicker on one side but this is usually invisible except with very powerful prisms. If ever you suddenly develop double vision you must see an eye care professional immediately as this can sometimes be a sign of serious underlying health problems, such as stroke and aneurysm.

Dry Eye

Oddly enough, one of the main symptoms of dry eye is watery eyes! They can also feel gritty, tired, or ‘like there is something in’ the eye. Many of us experience dry eye for a variety of reasons, and can go through phases of it improving and worsening. Lots of screen work and reading causes dry eye through lack of blinking, and modern environments can be very drying (think of air conditioning and car ventilation). Lubricant drops can be used to help but it is important to work out whether it is just dry eye causing your symptoms, or anything else. Our Optometrists can examine the surface of the eye very closely to work out what’s causing your symptoms and what might help!


Keratoconus is a progressive condition that causes the cornea to steepen and become ‘cone’ shaped rather than round; it causes high levels of astigmatism and distortion in the vision. It is more common in males and those who suffer with ‘atopic’ conditions such as asthma, eczema, hayfever and allergies. It can be detected during a normal eye examination and our Optometrists can advise on the best course of action; often contact lenses can be very helpful.

Lazy Eye (Amblyopia)

Some people are unable to see as well with one eye as the other, even with glasses. This can happen because of damage to the optic nerve or retina, or because one eye simply hasn’t ‘learned’ to see as well as the other. People with a lazy eye don’t often have any outward signs, as the other eye copes very well, but they don’t have good 3D vision ‘stereopsis’ so can struggle with certain tasks like catching a ball and judging distances. Lazy eye can be prevented in childhood in many cases, if it’s caught early enough. Glasses and sometimes temporary patching of the good eye are used to encourage the weaker eye to work better. We think for most children it’s difficult (but not impossible) to improve a lazy eye beyond about the age of 7; the earlier it’s found the better the chances of restoring ‘normal’ sight.


Leukocoria is a white appearance to the pupil. This can happen for several reasons but the most concerning of these is a condition called Retinoblastoma, a childhood cancer which affects infants and young children. If ever you notice your child has a white pupil (sometimes this shows best in photographs) please get them seen urgently by an eyecare professional.


Leukocoria is a white appearance to the pupil. This can happen for several reasons but the most concerning of these is a condition called Retinoblastoma, a childhood cancer which affects infants and young children. If ever you notice your child has a white pupil (sometimes this shows best in photographs) please get them seen urgently by an eyecare professional.