Fixation (visual)

Fixation (visual) refers to the process by which the eye maintains focus on a single point in the visual field. This is a crucial aspect of visual perception and is essential for activities such as reading, driving, and any task that requires detailed visual attention.

Mechanism

Fixation involves the coordination of several ocular muscles to keep the fovea, the central part of the retina responsible for sharp vision, aligned with the target. The brain plays a significant role in this process, integrating sensory information and controlling the extraocular muscles to maintain steady gaze.

Types of Fixation

There are several types of fixation:

• Steady fixation: The eye remains stationary on a single point.
• Saccadic fixation: Rapid movements of the eye between points of interest.
• Smooth pursuit: The eye smoothly follows a moving object.

Clinical Significance

Proper fixation is essential for clear vision. Disorders of fixation can lead to visual impairment and are often associated with conditions such as strabismus, nystagmus, and amblyopia. Ophthalmologists and optometrists assess fixation as part of a comprehensive eye examination.

Assessment

Fixation can be assessed using various techniques:

• Direct observation: Clinicians observe the patient's ability to maintain focus on a target.
• Eye tracking devices: These devices measure the precise movements of the eye to evaluate fixation stability.

Related Concepts

• Saccade
• Smooth pursuit
• Visual acuity
• Ocular motor system
• Retina
• Fovea

See Also

• Visual perception
• Eye movement
• Ophthalmology
• Optometry