Why Do I Have A Dark Spot In My Vision? By Dr Rupal Morjaria, Consultant Ophthalmologist

You are reading and suddenly notice that part of a word seems to disappear.

You look at someone’s face and there appears to be a small dark or blurred area in your vision.

Perhaps the spot moves when you move your eyes. Or perhaps it seems to stay in exactly the same place.

One of the questions patients understandably ask is:

“Why do I have a dark spot in my vision?”

There are several possible explanations.

Sometimes, a dark spot is caused by something relatively common, such as a floater. In other cases, particularly when the area is fixed, appears suddenly or affects your central vision, it can be a sign of a condition affecting the retina or macula.

As a Consultant Ophthalmologist and Medical Retina Specialist, I regularly assess patients who have noticed new spots, shadows or missing areas within their vision.

The important question is not simply whether you can see a dark spot.

It is what is causing it.

The short answer

A dark spot in your vision can have several possible causes, including:

• Floaters within the eye

• Changes affecting the vitreous

• Conditions affecting the retina or macula

• Diabetic eye disease• Macular degeneration

• A retinal tear or retinal detachment

One of the most useful distinctions is whether the spot moves around your vision or remains fixed in one place.

That can provide an important clue as to what may be causing the symptom.

Could the dark spot be a floater?

Possibly.

Floaters are small shapes that appear to move through your field of vision. They may look like dots, specks, threads, cobwebs or small shadows.

They are usually related to changes within the vitreous, the clear gel that fills much of the inside of your eye.

As the vitreous changes, small clumps or strands can cast shadows onto the retina. You perceive these shadows as floaters.

A typical floater often moves when you move your eyes and may appear to drift away when you try to look directly at it.

Floaters become increasingly common as we get older and many are harmless.

However, a sudden appearance of multiple new floaters should not automatically be dismissed as part of ageing.

If you suddenly develop new floaters alongside flashing lights, a shadow or a change in your vision, you should seek prompt ophthalmic advice.

What if the dark spot does not move?

A fixed area of missing or reduced vision is different from a typical moving floater.

The medical term scotoma describes an area of reduced or absent vision within your visual field.

Some people experience this as an obvious dark spot. Others notice something more subtle.

For example, part of a word may disappear when reading, an area of someone’s face may appear blurred or part of your central vision may seem to be missing.

If you develop a new fixed spot, particularly within your central vision, it is important to establish what is causing it.

Could a problem with the macula cause a dark spot?

Yes. The macula is the central part of the retina responsible for the detailed vision you use when reading, recognising faces, driving and looking at fine detail.

Conditions affecting the macula can therefore cause noticeable changes in the centre of your vision.

These may include:

• A blurred or grey central patch

• Distorted vision

• Straight lines appearing wavy

• Missing letters when reading

• Difficulty recognising faces

• Reduced ability to see fine detail

A new change affecting central vision deserves assessment, particularly if it appears suddenly or is becoming progressively worse.

Can macular degeneration cause a dark spot in my vision?

It can. Age-related macular degeneration affects the macula and can lead to deterioration in central vision.

Wet age related macular degeneration can sometimes cause more rapid visual changes because abnormal blood vessels develop underneath the retina. These vessels can leak fluid or blood and disrupt the normal structure of the macula.

You may notice blurred central vision, distortion, straight lines appearing wavy or a grey or dark area within your central sight.

The speed of the change is particularly important.

If you notice new distortion or a missing area within your central vision, it is sensible to seek specialist assessment rather than waiting to see whether it improves.

Can diabetes cause dark spots in my vision?

Diabetes can affect the small blood vessels within the retina, resulting in a condition called diabetic retinopathy. Changes to these blood vessels can lead to leakage, bleeding and other abnormalities at the back of the eye.

If bleeding occurs into the vitreous, you may notice new dark spots, floaters, cobweb shaped areas or hazy vision.

Diabetes can also cause swelling within the macula, known as diabetic macular oedema, which can affect central vision. Importantly, diabetic eye disease can develop before you notice significant changes to your eyesight.

This is why attending regular diabetic retinal screening remains important even when your vision appears normal.

Could a retinal tear or retinal detachment cause a dark shadow?

Yes and this is particularly important to recognise. A retinal detachment occurs when the retina separates from the tissue underneath it.

Symptoms can include:

• A sudden increase in floaters

• Flashing lights

• A dark shadow

• A curtain moving across part of your vision

• Loss of peripheral vision

• Sudden deterioration in sight

A retinal detachment is different from an occasional longstanding floater.

If a curtain or shadow suddenly develops across your vision, particularly alongside new flashes or floaters, you should seek urgent ophthalmic assessment.

Why might I only notice the dark spot in one eye?

Your brain normally combines visual information from both eyes.

If a relatively small visual defect develops in one eye, the other eye can sometimes compensate. This means you may not immediately realise anything has changed.

Some people only discover the difference when they happen to cover one eye.

If you notice an unusual visual symptom, comparing each eye separately can help you understand whether one or both eyes are affected.

However, a new or unexplained change should still be assessed appropriately.

How is a dark spot in the vision investigated?

The first step is understanding exactly what you are experiencing.

Important questions include when the spot appeared, whether it developed suddenly or gradually, whether it moves, whether one or both eyes are affected and whether you have noticed other symptoms such as flashes or distortion.

An ophthalmic examination then allows the structures inside the eye to be assessed, including the retina and macula. Depending on your symptoms and examination findings, further investigations may be appropriate.

OCT imaging can provide detailed cross sectional images of the retina and is particularly useful when investigating conditions affecting the macula. Other retinal imaging or investigations may also be recommended depending on what is found.

The purpose is not simply to confirm that there is an abnormality in your vision.

It is to establish why it has happened and whether treatment or monitoring is required.

Will the dark spot go away?

That depends on the underlying cause.

Some floaters can become less noticeable over time as your brain gradually adapts to them.

Other visual changes may improve when the underlying condition is treated.

However, if an area of the retina or macula has sustained permanent damage, some degree of visual change may remain.

Without identifying the cause, it is difficult to predict whether a dark spot will disappear.

When should I get a dark spot in my vision checked?

A new or unexplained dark spot is worth investigating, particularly if it remains fixed, affects your central vision or interferes with everyday activities such as reading or driving.

You should arrange an assessment if you notice a persistent dark or blurred area, new distortion, missing areas within your vision or symptoms that are becoming progressively worse. Some visual changes require more urgent attention.

Seek urgent ophthalmic advice if you experience:

• A sudden curtain or shadow across your vision

• Sudden loss or significant deterioration of vision

• A sudden shower of new floaters• New flashing lights alongside floaters

• Sudden loss of peripheral vision

When these symptoms occur, the retina should be assessed promptly.

Why seeing the right specialist matters

Different conditions affecting the vitreous, retina and macula can produce similar visual symptoms.

The important part of the assessment is therefore identifying where the problem is coming from and what it means for your vision.

As a Consultant Ophthalmologist and Medical Retina Specialist, I regularly diagnose, monitor and treat conditions affecting the retina and macula, including macular degeneration and diabetic eye disease.

A specialist assessment can help determine whether your symptoms require treatment, monitoring, further investigation or simply reassurance.

Not every dark spot represents a serious retinal condition.

However, when a symptom is new, persistent or changing, understanding the cause is important.

The bottom line

A dark spot in your vision can have several possible explanations.

The key points to remember are:

• A moving spot may be a floater

• A fixed area of missing vision may be a scotoma

• Conditions affecting the macula can alter central vision

• Diabetes and macular degeneration can both affect the retina

• Sudden flashes and new floaters can sometimes indicate a retinal problem

• A curtain or shadow across your vision requires urgent assessment

• New visual symptoms should not automatically be dismissed as part of ageing

Ultimately, the most useful question may not be:

“Will the dark spot go away?”

But:

“What is causing the dark spot in my vision?”

Ready to take the next step?

If you have noticed a new dark spot, blurred patch, distortion or missing area within your vision, a specialist assessment can help establish the cause.

Booking a consultation with Dr Rupal Morjaria can provide a detailed ophthalmic assessment, specialist examination of the retina and macula, appropriate retinal imaging and clear guidance on whether treatment or monitoring is required.

If you would like clarity about a new or unexplained change in your vision, I would be very happy to see you in clinic.

Contact details & appointments, click here.