Flashes of light, spots and flickering: visual disturbances such as mouches volantes & co – meaning and causes

Suddenly small black dots appear in the field of vision, flashes of light appear or vision seems to be through a flickering kaleidoscope – sounds spectacular, but can have very different causes. Are these just harmless mouches volantes, a migraine with aura or is there a serious eye condition behind them? In this article, you will find out what causes these visual disturbances, when you can remain calm and when it is better to see an ophthalmologist immediately. Because one thing is clear: your eyesight is too valuable to leave to chance!

What are flashes of light, spots and flickering?

Flashes of light, spots and flickering are visual phenomena that occur suddenly and can impairthe patient’s field of vision. They vary in their appearance and significance, but do not necessarily indicate a serious illness. They are often harmless, but in some cases they can be a warning sign of damage to the retina or a circulatory disorder in the brain.

Flashes of light (photopsies)

Flashes of light occur when the vitreous body pulls on the retina or changes. Patients may suddenly see bright flashes or short pulses of light, which are particularly noticeable in dark surroundings. These flashes can occur more frequently when the eyes move and spread across the outer field of vision.

Spots & mouches volantes

Many people occasionally notice black dots, threads or floating shadows – so-called mouches volantes. These are caused by the shrinkage of the gelatinous substance in the vitreous humor, resulting in the formation of small condensations that appear as moving spots in the patient’s field of vision. They often occur when the eye is moved back and forth.

Flickering in front of the eye

A flickering or zigzag pattern in the field of vision can be triggered by various factors. It is typical in the case of migraine with aura, where sufferers perceive a flickering light or pulsating zigzag pattern. In other cases, flickering in front of the eye can indicate fluctuations in blood pressure, circulatory disorders or even a stroke.

Causes of flashes of light and flickering in front of the eye

Flashes of light and flickering can be caused by various processes in the eye or brain. While some triggers are harmless, others can indicate a serious illness. The decisive factor is whether the symptoms occur suddenly, are associated with other visual disturbances or appear in both eyes at the same time.

1. changes in the vitreous body

• A vitreous detachment occurs when the vitreous detaches from the retina due to age. This often results in flashes of light, which occur particularly when the eyes move.
• Mouches volantes are caused by small condensations in the vitreous humor, which are perceived as floating spots or threads in the field of vision.

2. Retinal diseases

• A tear in the retina can occur if the vitreous body pulls too hard on the retina. This can lead to sudden flashes of light and, in severe cases, to retinal detachment.
• A hemorrhage in the vitreous body causes dark spots and can be caused by diabetes, high blood pressure or an eye injury.

3. neurological causes

• Migraine with aura often leads to a flickering or jagged pattern in the field of vision, which can occur in both eyes and typically disappears after 20 minutes.
• A circulatory disorder in the brain can lead to flashes of light or temporary loss of vision and can be a warning sign of a stroke.

4. other triggers

• A sudden drop in blood pressure can lead to short-term flickering in front of the eye.
• Drug abuse or certain medications can trigger visual perception disorders.
• Eye inflammation or a disorder of the immune system can also cause flashes of light.

Mouches Volantes – When spots and veils dance before your eyes

Mouches volantes (French for “flying midges”) are small shadows, dots or thread-like structures that appear in the field of vision and move when the eyes move. They are particularly visible against a light background, such as a blue sky or a white wall.

These visual phenomena are caused by changes in the vitreous body of the eye. With increasing age, the vitreous body begins to shrink, causing small condensations of the gelatinous substance to form. The light entering the eye then casts shadows on the retina, which are perceived as floating spots.

Are mouches volantes dangerous?

In most cases, mouches volantes are harmless and do not need to be treated. Although they can be disturbing, they are usually a normal age-related change. Nevertheless, there are situations in which they can be a warning sign of a more serious illness:

• If they suddenly occur in large numbers or are accompanied by flashes of light.
• If there is a tear in the retina or a hemorrhage in the vitreous body.
• If the field of vision suddenly darkens or shadows appear.

Anyone who notices a sudden increase in mouches volantes or other visual disturbances such as blurred vision or pressure in the eye should consult an ophthalmologist to rule out serious damage to the retina.

Flashes of light as warning signals – when should you see a doctor?

Not all flashes of light are harmless – in some cases they can indicate a serious eye condition. Caution is advised, especially if the flashes occur suddenly, are associated with other visual disturbances or only appear in one eye.

• See an ophthalmologist if:
  Sudden flashes of light in combination with many new mouches volantes may occur. This may indicate a detachment of the vitreous body or a tear in the retina.
• Dark shadows or a “curtain” appear in the field of vision – a possible sign of retinal detachment.
• Flashes of light can be accompanied by a sudden loss of vision – this can be an indication of a circulatory disorder in the brain or a stroke.
• Flashes or flickering in front of both eyes at the same time – this could indicate a migraine with aura or another neurological disorder.
• Additional symptoms such as headaches, dizziness or pressure in the eye are present.

Other temporary visual disturbances and their causes:

Flickering or spikes in front of the eyes can occur not only when you have rubbed your eyes. Other medical problems that are not directly related to the eyes can also be the trigger.

Migraine with aura

A migraine with aura is a special form of migraine in which visual disturbances occur before the actual headache. Those affected often see flickering zigzag patterns, flashes of light or blurred areas in their field of vision, which slowly spread and disappear after around 20 minutes. These visual symptoms are caused by a temporary circulatory disturbance in the brain, which impairs the processing of visual information.

• Flickering or spikes in the field of vision, often with a shimmering edge.
• Blind spots or bright dots that move across the patient’s field of vision.
• Sensitivity to light and sometimes reddening of the eyes.
• The aura phase is often followed by a severe, pulsating headache, often on one side of the head.

Not every migraine attack is accompanied by an aura, and not every aura leads to a headache. Some people only experience the visual disturbances without experiencing a headache afterwards.

Fluctuations in blood pressure

Fluctuations in blood pressure can not only affect your general well-being, but also your eyesight. In particular, a sudden drop or sharp rise in blood pressure can lead to flickering in front of the eyes, flashes of light or blurred vision. The reason: the eye is heavily dependent on blood flow – if it is not supplied with sufficient oxygen for a short time, this can lead to visual disturbances.

Typical visual disturbances due to fluctuations in blood pressure:

1. Sudden lighting or flickering in the field of vision, often in both eyes.
2. Blurred vision that disappears again after a short time.
3. Dark spots or tunnel vision when the brain receives less oxygen for a short time.
4. Dizziness or light-headedness, often accompanied by general weakness.

When do these symptoms occur?

• When suddenly standing up from a sitting or lying position (orthostatic hypotension).
• In cases of severe stress or anxiety, when blood pressure suddenly rises.
• After intensive physical exertion, when the circulation first has to stabilize again.
• For low blood sugar, especially in people with diabetes.

Diabetes & eye problems

Diabetes can affect eye health in the long term and is one of the most common causes of visual impairment. High or highly fluctuating blood sugar levels can damage the blood vessels in the retina, which can lead to blurred vision, flashes of light or even partial loss of vision.

• Diabetic retinopathy – damage to the fine blood vessels of the retina, which can lead to visual impairment, mouches volantes or bleeding in the vitreous humor.
• Diabetic macular edema – accumulation of fluid in the macula that impairs central vision.
• Sudden fluctuations in vision – In the short term, high blood sugar can change the curvature of the lens, causing the patient’s field of vision to appear blurred.
• Increased risk of cataracts and glaucoma – Diabetes accelerates lens opacification and can increase intraocular pressure.

What can be done about the causes of flashes of light and mouches volantes?

The treatment of flashes of light, spots or flickering in front of the eyes depends largely on the cause. In many cases, these phenomena are harmless and do not need to be treated, but sometimes they can indicate a serious illness that requires medical clarification. It is therefore important to observe exactly when and in which situation the visual disturbances occur, whether they change or are accompanied by other symptoms.

What to do in case of vitreous detachment?

If mouches volantes are caused by vitreous detachment, there is usually no need for action as the brain becomes accustomed to the floating spots over time. However, those affected should consult an ophthalmologist if many new spots suddenly appear or if flashes of light can also be seen, as this may indicate retinal damage. If a tear in the retina is detected, it can be sealed with laser treatment to prevent retinal detachment.

What to do for migraine with aura?

If flickering or jagged lines appear in the field of vision and disappear after around 20 minutes, this could be caused by a migraine with aura. In this case, it helps to retreat to a quiet, darkened environment and avoid possible triggers such as stress or lack of sleep. Anyone who regularly suffers from migraine attacks should keep a migraine diary to identify individual triggers.

Serious signs of light flashes

If flashes of light or flickering occur in both eyes at the same time, there may be a circulatory disorder in the brain. A sudden drop in blood pressure, which can occur when standing up quickly, is usually harmless. However, if the blurred vision lasts longer or occurs with dizziness, numbness or speech disorders, a doctor should be consulted urgently, as this could indicate a serious circulatory disorder or a stroke . Retinal detachment can also be the cause and requires immediate consultation with an ophthalmologist.

Blood glucose control for diabetes

In the case of diabetes-related eye problems, good blood sugar control is crucial to prevent damage to the retina. Anyone who regularly suffers from fluctuations in visual acuity or notices dark spots in their field of vision should have an eye examination carried out promptly in order to detect possible diabetic retinopathy at an early stage.