Prismatic Lens as Post stroke glasses for Binocular Vision Dysfunction.

Prismatic Lens as Post stroke glasses for Binocular Vision Dysfunction.

A stroke can be a life-altering event, often leaving survivors with a range of physical and cognitive impairments. One such impairment is post-stroke visual field loss, a condition that can severely limit a person’s ability to navigate their environment and perform daily tasks. However, recent advancements in optical technology, specifically the development of prismatic lenses, offer a ray of hope for those grappling with this issue.

Emergence of Prismatic Lens as Post stroke glasses

Prismatic Lens as Post stroke glasses for  Binocular Vision Dysfunction.

Prismatic Lenses and Post-Stroke Visual Field Loss

Prismatic lenses are specialized optical devices that can expand the field of vision for stroke survivors suffering from visual field loss. These lenses work by shifting the light entering the eye, effectively broadening the visual field and compensating for the lost vision. This can significantly reduce the risk of bumping into objects, falling, and other potential injuries.

The use of prismatic lenses can also enhance a patient’s ability to read text and move around in their environment, thereby improving their overall quality of life.

Read- Microprism and BVD

Addressing Binocular Vision Dysfunction

In addition to visual field loss, many stroke survivors develop binocular vision dysfunction, a condition where the two eyes fail to work together as a team. This can lead to a host of uncomfortable symptoms, including discomfort, dizziness, headaches, eye strain, anxiety, and pain.

Realigning prismatic lenses can be used to treat binocular vision dysfunction effectively. By adjusting the visual input to both eyes, these lenses can help restore binocular vision and alleviate the associated symptoms.

Unfortunately, many patients suffer from these symptoms for years without receiving a proper diagnosis or treatment. Raising awareness about the potential benefits of prismatic lenses is therefore crucial.

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Case Studies and Research Findings on visual field loss following stroke

Biomechanical Changes to Visual Field Loss Following Stroke: A systematic review was conducted to gather evidence on the biomechanical changes to visual field loss following stroke1. The review included randomized controlled trials, cohort studies, before-after studies, and case-controlled studies. The studies investigated eye, head, or body movements in post-stroke visual field loss during visual exploration tasks (1)

The review found that hemianopic participants and healthy adults with simulated hemianopia differed significantly from controls in various fixation and saccade parameters. This suggests that there are considerable alterations in eye movements in true hemianopia and in healthy adults with simulated hemianopia

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Prism Adaptation Therapy for Patients with Subacute Stroke: Ref (2)

A multicenter, double-masked, randomized, controlled trial was conducted to evaluate the effects of a 2-week prism adaptation therapy on unilateral spatial neglect (USN) in patients with subacute stroke. The study found that the Functional Independence Measure (FIM) improved significantly more in the prism group. In patients with mild USN, there was significantly greater improvement of the Behavioral Inattention Test (BIT) and FIM in the prism group. This suggests that prism adaptation therapy can significantly improve activities of daily living in patients with subacute stroke.

Case Series on Use of Prism Glasses and Intensive Upper Limb Exercise:

A case series was conducted involving the use of prism glasses and intensive upper limb exercise for stroke patients. The study aimed to examine the effects of visual field with prism glasses, and intensive upper limb functional training on reduction of hemineglect and improvement in upper limb function and activities of daily living in three stroke patients with hemineglect. The study found that subjects’ hemineglect decreased and upper limb function on the paretic side improved after intervention, which enhanced activities of daily living.


These studies highlight the potential of prismatic lenses and prism adaptation therapy in improving the quality of life for stroke patients suffering from visual field loss and binocular vision dysfunction. However, more research with robust methodology and large sample sizes are needed to further validate these findings.

It is important to visit a specialized eye doctor after a stroke to receive formal visual field testing. The doctor will test and document which areas of the visual field have been affected, and create a baseline from which to compare if the patient experiences any visual field loss in the future.

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