Visual Skills Flashcards
What is visual perception and why is it important for daily functioning?
Visual perception is the brain’s process of transforming raw visual data into meaningful images of the environment. This process is essential for understanding our surroundings, interacting with objects, and navigating safely.
Explain the concept of contrast sensitivity function and its role in visual acuity.
Contrast sensitivity function refers to the ability to detect the edges of objects as their contrast with the background decreases. It’s a crucial component of visual acuity as it allows us to perceive details and subtle differences in shades and textures.
Differentiate between myopia and hyperopia, and describe how they affect vision.
Myopia, or nearsightedness, causes blurry distance vision due to the eye focusing light in front of the retina. Hyperopia, or farsightedness, leads to blurry near vision as light focuses behind the retina. Both conditions require corrective lenses to adjust the focal point.
How does the assessment of visual acuity take into account a client’s use of corrective lenses?
When assessing visual acuity, clients should wear their prescribed glasses or contact lenses (“best correction”). This ensures the measurement reflects their optimal visual capability with the aid of their corrective lenses.
What is homonymous hemianopia, and how does it typically manifest in a stroke patient?
Homonymous hemianopia is the loss of half of the visual field in both eyes. A stroke affecting the right hemisphere typically causes left homonymous hemianopia, meaning the left half of the visual field is lost in both eyes. The opposite occurs with a left hemisphere stroke.
Describe the phenomenon of perceptual completion and its impact on an individual’s awareness of visual field deficits.
Perceptual completion is the brain’s tendency to “fill in” missing visual information based on expectations and past experiences. This can make it difficult for individuals with visual field deficits to recognize their limitations, as their brain compensates for the missing input.
Explain how visual field deficits can impact a client’s reading abilities.
Visual field deficits can significantly hinder reading by reducing the number of characters a person can see with each eye fixation. This leads to slower reading, frequent re-reading, and difficulty tracking lines of text, particularly with hemianopia affecting the dominant hand side.
Differentiate between focal attention and ambient attention, providing examples of how each is used in daily life.
Focal attention is used for detailed observation and identification of specific objects, like reading text or recognizing faces. Ambient attention, also known as peripheral attention, monitors the surrounding environment for potential threats and guides movement, like avoiding obstacles while walking.
Why is it important to distinguish between hemi-inattention and visual field deficits during assessment?
Distinguishing between hemi-inattention and visual field deficits is crucial for effective treatment. Hemi-inattention, often associated with right hemisphere damage, involves a lack of attention to one side of space despite intact visual pathways. This differs from a visual field deficit where sensory input is physically lost.
What are saccades, and how do they contribute to efficient visual exploration?
Saccades are rapid, jerky eye movements that shift the gaze between different points of interest. They are essential for efficiently scanning the environment, reading, and quickly focusing on relevant visual information.
