HESS CHART CLOTH MODEL

The Hess screen test is based on the haploscopic principle. It was popularized by Lyle, in particular for diagnosing possible paretic or paralytic conditions in patients with normal correspondence. 

Principles  Dissociation Foveal projection  Hering’s and Sherrington’s Laws of Innervation 

To perform this test, a black cloth 3 ft wide by 31⁄2 ft long, marked out by a series of red lines subtending between them an angle of 5°, is used.  At the zero point of this coordinate system and at each of the points of intersection of the 15° and 30° lines with one another and with corresponding vertical and horizontal lines, there is a red dot.  These dots form an inner square of 8 dots and an outer square of 16 dots. 

ZABBYS HESS SCREEN CLOTH MODEL Z-HESS-C Hess Screen Unmounted is made of heavy BLACK fabric. Target is printed in Red ink and is invisible with red or green glasses. Screen Grid area is approximately 60 inches square (150 x 150 cm) and comes folded for ease of shipment. Folding screen can be mounted to a tack board or hung with a clamp at the top like a carpet for display.