How Does Dementia Affect Vision?
Vision is complex and requires various parts of the brain to process and understand what our eyes see. A basic knowledge of the different lobes of the brain that contribute to visual processing can be helpful to understand changes that can occur when someone is living with dementia.
Occipital Lobe: This lobe is the visual processing hub of the brain, receiving and processing raw visual information from the eyes.
Parietal Lobe: Plays a crucial role in visual processing, particularly in spatial awareness, visuomotor control, and visual attention. It helps us understand where objects are in space and how to interact with them.
Temporal Lobe: Is associated with object recognition and assigning meaning to what is seen. It helps identify and categorize objects, including faces and places.
Frontal Lobe: Is not considered a primary visual area, but it contributes to visual processing by guiding attention, controlling eye movements, and integrating visual information.
Visual processing can be significantly impaired in individuals living with dementia due to the death of neurons (brain cells) and the breakdown of their connections, which are crucial for communication between different parts of the brain. Individuals with dementia may have difficulty interpreting what they see, leading to challenges in recognizing familiar objects, faces, or places. This can result in confusion and disorientation.
Impaired Visual Perception examples:
1. Depth Perception Issues: Dementia can affect depth perception, making it difficult for individuals to judge distances accurately. This can increase the risk of falls and accidents, as they may misjudge the height of steps or the distance to objects.
2. Visual Agnosia: A condition where they can see objects (e.g. toothbrush, fork or spoon) but cannot recognize or identify them. This can lead to frustration and difficulty in performing daily activities.
3. Difficulty with Visual Scanning: Is the ability to move your eyes across a visual field to locate objects or information. This can affect their ability to read, follow conversations, or navigate their environment.
4. Contrast Sensitivity: Decreased contrast sensitivity can make it harder to distinguish between objects and their backgrounds, especially in low-light conditions.
5. Changes in Visual Attention: Dementia can lead to difficulties in maintaining attention on visual tasks, resulting in challenges when trying to focus on specific objects or activities.
6. Peripheral vision: Individuals with dementia may experience a narrowing of their visual field, like looking through binoculars, making it harder to see things to the side.
Strategies can be tailored to the individual needs of the person living with dementia and should be implemented with consideration of their functional abilities and goals.
Examples of Strategies:
Lighting: Ensure that living spaces are well-lit to reduce shadows and enhance visibility. Use natural light when possible and consider night lights in hallways and bathrooms.
Clutter Reduction: Minimize clutter in the environment to help the focus on important objects and reduce confusion.
Contrasting Colors: Use contrasting colors for furniture, walls, and floors to help distinguish between different surfaces and objects.
In conclusion, the visual processing deficits associated with dementia can signficantly impact a person’s ability to perform daily activities, such as dressing, cooking, and navigating their home safely. Understanding the impact of dementia on visual processing is crucial for caregivers and healthcare providers. By recognizing these challenges, appropriate strategies can be implemented to enhance safety, promote independence and improve the overall quality of life for individuals with dementia.
Written by: Susan Raychard, MOTR/L, CDP, Positive Approach to Care Ind, Trainer.
