Fresnel Prism on Hess Screen Test

Fresnel Prism on Hess Screen Test

A 65-year-old male patient complained of diplopia after a cataract surgery. He had esotropia of 18 prism diopters (PDs) at distant and near deviation, and therefore, we performed the Hess screen test to identify any abnormal eye movement. However, the indicator was found to be out of bounds, and therefore, the test could not be completed. Therefore, the test was subsequently performed with a 20...

The hess screen test.

The Hess screen test was designed by Walter Rudolf Hess in 1908 with subsequent modifications.(1, 2) Hess was a famous neurophysiologist who was awarded the Nobel Prize in 1949 for his research into the functional organization of the vegetative nervous system.(3, 4) The original test used a black screen on which was marked a square-meter tangent scale. The tangent nature of the coordinate lines...

Fresnel Zones on the Screen

Hess Lancaster screen test with the head tilted: a useful test in the diagnosis of bilateral fourth nerve palsies.

PURPOSE To introduce Hess Lancaster screen test performed with the head tilted as a new ancillary test to help in the diagnosis of bilateral superior oblique (SO) nerve paresis. METHODS Three patients with clinical diagnosis of acquired bilateral fourth nerve paresis, three with clinical diagnosis of acquired unilateral fourth nerve paresis, and three normal subjects were tested with Hess Lan...

A comparison of the effect of 3M Fresnel prisms and Trusetal prism foils on visual function

Aim: To determine any differences in visual acuity (VA) and contrast sensitivity (CS) between 3M Fresnel prisms and Trusetal prisms foils. Methods: Sixteen participants (mean age 20 years) with normal VA and CS participated. The effect of 5D, 10D, 20D and 30D prism strengths on monocular VA and CS was assessed using a Bailey-Lovie logMAR chart and Pelli-Robson chart, respectively. Measurements ...