Common Eye Conditions Found During an Eye Test (and What They Mean for You)

Most people book an eye test to update a prescription or pick out new glasses. That matters, but it is only part of what happens in the chair. A thorough eye examination is also a genuine health check, and it can pick up the early signs of conditions that have no symptoms at all in their first stages.

That is the part worth understanding. Several of the most serious eye conditions are quiet to begin with. You will not feel them, and you may not notice any change in your vision until damage has already been done. The earlier they are found, the more can usually be done about them.

Here is a plain-English guide to five conditions a careful eye examination can flag early: glaucoma, age-related macular degeneration, cataracts, diabetic retinopathy and dry eye. We will explain what each one is, what you might notice, how an eye test picks it up, and what happens next.

The five conditions at a glance

Here is the short version before we look at each one in turn.

1. Glaucoma

Glaucoma is a group of conditions that damage the optic nerve, the cable carrying what you see from your eye to your brain. In most cases, the damage is linked to the pressure of the fluid inside your eye being too high for that particular nerve to cope with.

It is sometimes called the silent thief of sight, and the nickname is earned. Chronic glaucoma, the most common form, usually has no symptoms early on. Sight is lost so gradually, and from the edges of your vision inwards, that most people do not notice until a fair amount has already gone. Once sight is lost to glaucoma, it cannot be brought back.

The reassuring part is that an eye test can spot the early signs long before you would. Your optometrist looks at the optic nerve at the back of your eye, measures the pressure inside your eye, and checks how far your vision extends around the edges. Often, at least two of these are done together, because you can have glaucoma even with normal eye pressure.

If we see something that suggests glaucoma, we refer you to an ophthalmologist for a formal diagnosis. There is no cure, but it is very treatable, usually with daily eye drops that lower the pressure and protect the sight you have. This is exactly why regular eye examinations matter, particularly if glaucoma runs in your family, you are over 40, or you are of African-Caribbean heritage, all of which raise your risk.

More on this condition: College of Optometrists guidance on glaucoma.

2. Age-related macular degeneration (AMD)

AMD affects the macula, the small but vital part of your retina responsible for your sharp, central, detailed vision. It is what you use to read, recognise faces and see fine detail. AMD is the leading cause of sight loss in the UK, though it is worth saying clearly that most people who have it keep enough vision to get around, because the edges of their sight are usually unaffected.

There are two types. Dry AMD is the most common and develops slowly over years, often with little noticeable change at first. Wet AMD is less common but more urgent. It happens when abnormal blood vessels grow and leak beneath the macula, and it can cause a sudden, rapid loss of central vision.

What might you notice? Things may look blurry even with your usual glasses; straight lines such as door frames might appear wavy or bent, or you might see a smudge that does not clear in the middle of your vision. These signs are easier to spot if you check each eye on its own, because a stronger eye will often cover for the other.

During an eye examination, we look closely at the macula at the back of your eye, often using a wide-view Optomap retinal scan that captures it in detail and can flag the earliest changes. Your risk rises as you get older, and you are more likely to develop AMD if you smoke or have a family history of it. There is currently no treatment for dry AMD, though stopping smoking, eating well and protecting your eyes from UV can help slow it. Wet AMD can often be treated with injections if it is caught early, which is why any sudden change in your central vision should be checked straight away.

More on this condition: College of Optometrists guidance on AMD.

3. Cataracts

A cataract is simply the clouding of the clear lens inside your eye. For most of us, it is a normal part of getting older, and it develops slowly, which is why many people do not notice it at first.

As a cataract develops, you might find your vision becoming less sharp, as though you are looking through a slightly misted window. Car headlights and streetlights can start to dazzle, colours can look faded or washed with yellow, and moving from shade into bright sun can feel awkward. Some long-sighted people even find they need their glasses a little less for a while.

Cataracts show up clearly during an eye examination, when we examine the lens under magnification with a slit lamp. They become more likely as you get older, and smoking, heavy sun exposure without UV protection and drinking a lot of alcohol can all bring them on sooner. In the early stages, a change of glasses prescription can keep you comfortable.

When a cataract starts to get in the way of everyday life, such as driving, reading or cooking, the answer is a straightforward and very common operation that replaces the cloudy lens with a clear artificial one. It is one of the most successful procedures in modern medicine, and we can refer you to an ophthalmologist when the time is right.

More on this condition: College of Optometrists guidance on cataracts.

4. Diabetic retinopathy

If you live with diabetes, this is the one to know about. Diabetic retinopathy happens when persistently high blood sugar damages the tiny blood vessels in your retina, causing them to leak or become blocked. It affects people with both type 1 and type 2 diabetes, and it is one of the leading causes of preventable sight loss in the UK.

Like glaucoma, it is quiet at first. In the early stages, there are usually no symptoms at all, and your vision can seem perfectly normal even while changes are taking place at the back of your eye. That is precisely why it is so important not to wait for something to feel wrong.

If you have diabetes and are aged 12 or over, you should be invited to the NHS diabetic eye screening programme, which takes detailed photographs of your retina. That screening is important, and a routine eye test does not replace it. What a thorough eye examination with us adds is another expert look at the blood vessels in your retina between screenings, often with the same wide-view Optomap scan, so related changes can be picked up and talked through with you. The longer you have lived with diabetes, and the less tightly your blood sugar, blood pressure and cholesterol are controlled, the greater the risk, so managing those things makes a real difference. Caught early, retinopathy is very treatable.

More on this condition: College of Optometrists guidance on diabetic retinopathy.

5. Dry eye

Dry eye is the odd one out on this list. It is rarely sight-threatening, but it is genuinely uncomfortable, surprisingly common, and well worth sorting out properly. It happens when there is a problem with your tear film, either because your eyes are not making enough tears or because the tears you have evaporate too quickly.

The symptoms are easy to recognise once you know them. Your eyes might feel gritty or sore, as though there is something in them. They can look red, feel tired by the end of the day, or water more than usual, which sounds back to front but is a classic sign. Vision can even blur a little between blinks.

Plenty of things make it more likely, including getting older, screen-heavy days, contact lens wear, certain medications, air conditioning and hormonal changes. During your eye care appointment we can assess your tear film and the glands along your eyelids to work out what is actually driving it, then suggest a plan that fits, from simple lubricating drops to small changes in your daily habits. The right approach depends on the cause, which is why it is worth having it looked at rather than guessing.

More on this condition: College of Optometrists guidance on dry eye.

What a thorough eye examination actually involves

You may have noticed a theme running through all five of these conditions. Most give you little or no warning, so the eye test is doing the noticing on your behalf. That is the real value of a careful, unhurried examination. It is not only about whether you need glasses.

At Perspective, every eye examination is led by an optometrist from start to finish, and we give it the time it deserves rather than rushing you through. We examine the front and back of your eye, including a wide-view Optomap retinal scan that captures the back of the eye in moments and often avoids the need for dilating drops, check your pressures and assess your vision properly, so that anything unusual is spotted early. When something needs a specialist, we have an established referral pathway to leading ophthalmologists, so you are never left wondering what to do next.

It is the kind of attentive, personal care that is harder to find on the high street, and it is why people come to us from across Belsize Park, Hampstead, Primrose Hill and Camden.

Frequently asked questions

How often should I have an eye test?

For most adults, every two years is the general guidance, but some people are advised to come more often, for example, if you are over 40, have a family history of glaucoma, or live with diabetes. We will always tell you what is right for you.

Can an eye test really detect conditions before I notice symptoms?

Yes, and that is one of its most important jobs. Glaucoma, diabetic retinopathy and early AMD often have no symptoms at all to begin with, yet the signs are visible to an optometrist during a thorough examination.

Do these conditions only affect older people?

Many are more common with age, but not all. Diabetic retinopathy can affect younger adults with diabetes, and dry eye is increasingly common at any age thanks to screens and contact lenses. Regular eye tests matter at every stage of life, which is why we also offer children’s eye examinations.

What happens if you find something during my eye test?

We will explain clearly what we have seen and what it means in plain language. If it needs a specialist, we will arrange a referral to an ophthalmologist through our established pathway and make sure you understand the next steps.

Does a private eye test replace NHS diabetic eye screening?

No. If you have diabetes, your NHS diabetic eye screening is important, and you should attend it. A thorough eye examination with us works alongside it, offering another expert look at your eye health between appointments.

Related reading

If you found this helpful, these two guides are a natural next step.

• How to prepare for your eye examination, a simple checklist for getting the most from your appointment, including the family history worth mentioning.
• NHS and private eye care, a friendly guide, explaining who qualifies for NHS sight tests and how funded and private care fit together.

The takeaway

Your eyes are very good at hiding problems until they are advanced, which is exactly why a regular, thorough eye test is one of the simplest things you can do for your long-term health. Conditions like glaucoma, AMD, cataracts, diabetic retinopathy and dry eye are far easier to manage when caught early, and often the only way to catch them early is to look.