Benefits of Marsden Red Ball Training: During practice, you can use an eye patch to cover the better-vision eye or wear red-green filter glasses. Using an eye patch can improve eye movement, tracking ability, and depth perception, while using filter glasses helps improve binocular vision. When wearing filter glasses, the image received by each eye is split into two parts, thus forcing the brain to begin using both eyes simultaneously. Who is Marsden Ball Suitable For? It is suitable for people with binocular vision impairments, such as amblyopia, strabismus, low vision, and other vision problems. It can be used by both children and adults. Examples include: difficulty using both eyes, hand-eye coordination disorders, eye-tracking disorders, amblyopia (lazy eye), strabismus (crossed eyes), convergence insufficiency, reduced depth perception, visuospatial processing disorders, visual-motor integration disorders, brain injury, autism spectrum disorders, etc. (Differences may occur between batches, but this will not affect the use of the product.) Color: As Shown Material: ABS Package Contents: 1 * Marsden ball