Vision Loss And Dizziness: Stroke Symptoms And Effects

A stroke can cause dizziness and loss of vision. Vertigo, or dizziness, is responsible for an estimated 4.4 million emergency department visits in the United States each year. Strokes are the underlying cause of 3% to 5% of these visits. Vision loss can also occur after a stroke, affecting up to 66% of survivors. This may be due to damage to the brain, which can affect the patient's daily life and overall recovery.

Visual field loss

Types of Visual Field Loss

The most common type of visual field loss after a stroke is hemianopia, which is the loss of one half of the visual field in each eye. This can make reading difficult, as words and sentences disappear when they fall within the missing visual field. It can also cause difficulties with locating objects and navigating, especially in unfamiliar or crowded places.

Another type of visual field loss is scotoma, which is a small patch of vision loss, often near the centre of the visual field. This type of loss is less common than hemianopia.

Diagnosis and Treatment

Prognosis

Eye movement problems

A stroke can lead to a variety of eye movement problems, resulting from damage to the nerves that control the eyes. These problems can include:

• Impaired eye movements: Difficulty moving eyes between objects or following a moving object, such as someone walking past. This can make reading more challenging and affect general mobility, such as walking outside.
• Inability to move both eyes together: If the nerve control to the eye muscles is affected, one eye may not move correctly, resulting in blurred or double vision (diplopia).
• Wobbling eyes: This condition is called nystagmus and can make it difficult to focus on objects, causing moving images and/or double vision.
• Impaired depth perception and difficulty locating objects: For example, misjudging the position of a cup when making tea and pouring water over the edge.

Treatment options for eye movement problems after a stroke include exercises, prisms, and patching. Exercises can help improve eye movement and coordination. Prisms can be used to eliminate double vision by redirecting light to the correct part of the retina. Patching involves covering one eye with a patch to avoid double vision and make it easier to see.

It is important to seek medical advice and undergo a comprehensive eye examination to determine the most appropriate treatment plan for eye movement problems following a stroke.

Visual processing problems

• Difficulty recognising objects, colours, faces, complex scenes, or text.
• Difficulty reaching for objects or seeing more than one object at the same time.
• Visual inattention or neglect, where one is unaware of things on one side of them, often caused by a stroke on the right side of the brain. This can cause people to ignore food on one half of their plate, not apply makeup to one side of their face, or bump into objects.
• Visual hallucinations, also known as Charles Bonnet syndrome, where the brain generates images in the missing area of vision.

Other sight problems, including light sensitivity

Light sensitivity is a common occurrence after a stroke. This may manifest as a bother or irritation caused by bright light or glare from light-coloured surfaces. Some people find that wearing tinted glasses or specially designed eye shields helps to ease the discomfort. Tinted glasses can also be used to reduce glare, with some people finding that a yellow or orange-tinted overlay helps to reduce glare. Brown-tinted sunglasses are also recommended.

Light sensitivity can occur when the brain has difficulty adjusting to different levels of light. This can cause bright lights to be uncomfortable.

In addition to light sensitivity, other vision problems can occur after a stroke, including:

• Dry eye: This can be caused by problems with the nerves of the eyelid, the facial nerve, or the muscles of the eyelid. The rate at which you blink may be slower after a stroke, and you may not be able to close your eyelids completely. Using artificial tear eyedrops, ointments, and reminding yourself to blink often and completely can help manage dry eye.
• Visual hallucinations (Charles Bonnet syndrome): Visual hallucinations occur when the brain generates images in the missing area of vision. These images often appear in the blind area and can be simple patterns or complex images of people and places. Visual hallucinations caused by sight loss are not a symptom of a mental health problem. They often improve over time as the brain gets used to the loss of vision. Organisations such as the Royal National Institute of Blind People (RNIB) and Esme's Umbrella provide support and raise awareness of the condition.
• Retinal vessel occlusion: This is caused by a blockage in the blood vessels to the retina, resulting in a reduction of blood supply to the eye. It shares many risk factors with stroke, such as high blood pressure, diabetes, and high cholesterol.
• Eye movement problems: A stroke can lead to impaired eye movements, difficulty moving both eyes together, constant eye movement or wobbling (nystagmus), and impaired depth perception. Treatment options include exercises, prisms, and eye patches.
• Visual processing problems: Some vision problems after a stroke are due to the brain's difficulty in processing information received from the eyes and other senses. This can manifest as difficulty recognising objects, colours, or faces, or challenges in reaching for objects or seeing multiple objects simultaneously.
• Visual inattention (visual neglect): This is a common type of visual processing problem where individuals are unaware of things on one side of them. It is often due to strokes on the right side of the brain, affecting the left side of the visual space. Individuals with visual inattention may ignore people or objects on their affected side, bump into things, or have difficulty drawing attention to their affected side.

It is important to note that vision problems after a stroke can vary depending on the location and extent of the stroke in the brain. Rehabilitation and assessment by eye care specialists are crucial for managing and treating these vision problems.

Vertigo

There are several tests available to diagnose vertigo and other forms of dizziness, such as the caloric test, which involves tracking eye movements while focusing on a moving object, and the posturography test, which evaluates balance under various conditions. If you are experiencing vertigo symptoms, it is important to consult a physician for proper diagnosis and treatment.

While dizziness and blurred vision can be warning signs of a stroke, they can also indicate vertigo. It is crucial to be aware of these symptoms and seek medical attention to determine the underlying cause.

Frequently asked questions