? What is the hole occluder? A hole occluder is an opaque disk with one or more small holes through it, used by ophthalmologists, orthoptists and optometrists to test visual acuity. The occluder is a simple way to focus light, as in a pinhole camera, temporarily removing the effects of refractive errors such as myopia. Because light passes only through the center of the eye's lens, defects in the shape of the lens (errors of refraction) have no effect while the occluder is used. ? What does the hole occluder do? The ophthalmologist, orthoptist or optometrist can estimate the maximum improvement in a patient's vision that can be attained by lenses to correct errors of refraction. This can be used to distinguish visual defects caused by refractive error, which improve when the occluder is used, from other problems, which do not. The hole occluder can also be used in testing visual acuity in mydriatic patients. In this case the pinhole occluder compensates for the inability to contract the iris assisting the eye in obtaining a retinal projection similar to that of a non-cycloplegic eye. ? How to use? Squinting and looking through a tiny hole made with a finger works similarly to a hole occluder, by blocking light through the outer parts of the eye's lens. An improvised pinhole has a similar but better effect. The same principle has also been applied as an alternative to corrective lenses: a screen of holes is mounted on an eyeglass frame and worn as pinhole glasses. ? Differential diagnosis : pinhole worsen vision: Macular diseases, central lens opacities Vision static with hole: Amblyopia

?Customer Satisfaction Guarantee?If you are not 100% satisfy with the purchase for any reason, don't hesitate to contact us to request a refund or replacement. Various color options to choose from: black & blue & purple. Occluder is a versatile tool, it provides so many features for Ophthalmic and Optometric exams. Occluder is suitable for patients of any age, even children catch on quickly. Multiple hole occluder flipper made of high impact resistant plastic. Can be sterilized with any non-solvent based germicide.

Best Sellers Rank: See Top 100 in Industrial & Scientific. Age Range (Description): Kid. Number of Items: 1. Item Dimensions LxWxH: 6.1 x 4.92 x 0.2 inches. Item Weight: 45 Grams. Brand: Medarchitect. : B073GX97GQ. Manufacturer: Medarchitect. Date First Available: November 10, 2019. Item model number: UL005. Product Dimensions: 6.1 x 4.92 x 0.2 inches; 1.59 Ounces. Is Discontinued By Manufacturer: No.