Hess screen

Hess screen

a screen used in the measurement of ocular deviation.
Farlex Partner Medical Dictionary © Farlex 2012


Carl von, German ophthalmologist, 1863-1923.
Hess capsule iris forceps
Hess expressor
Hess eyelid operation
Hess lens scoop
Hess lens spoon
Hess ptosis operation
Hess screen - a screen used in the measurement of ocular deviation.
Hess tonsil expressor
Medical Eponyms © Farlex 2012

screen, Hess

A black tangent screen for measuring and classifying strabismus. It consists of a chart divided by red lines into small sections of 5º separations. As the screen is flat, the lines are curved in a pincushion pattern (i.e. the middle of the lines is closer to the centre of the screen than the ends of the lines). At the respective positions on the lines in the eight major meridians are small red dots indicating positions 15º and 30º from the fixation point. Two green threads extend from the upper corners of the screen and meet a third green thread, which originates on the end of a pointer. The three threads form a figure Y. The patient, wearing a red lens in front of one eye and a green lens in front of the other, moves the pointer until the common origin of the green threads is superimposed on each of the red dots. The discrepancy between the two on the screen indicates the extent of the deviation in various directions of gaze. It is a particularly useful test to indicate an incomitant strabismus as the field plots obtained with each eye are compared and an estimate of which muscle/s is affected can be made. Moreover, if the inner (15º) and outer (30º) plots are affected differently the incomitancy is of mechanical origin. Note: there exists a computerized version of the Hess screen.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Deviation was measured with a prism cover test, torsion was measured by double Maddox rod test, and extraocular muscle function was assessed using a Hess screen. Diagnosis of SO palsy was made based on limited depression on adduction, IO hyperfunction, V-pattern, hypertropia, abnormal head position, excyclotorsion findings, and medical history.
Bilaterally reduced SO muscle function was observed on Hess screen test (Figure 2C), while binocular visual field test revealed single vision in the superior visual field (Figure 2D).
Bilateral SO muscle hypofunction was observed in Hess screen test and binocular visual field testing revealed diplopia on downgaze.
Thomson also provides software for controlling a Nidek phoropter, screening and prescribing tinted lenses for Miles-Irlen syndrome, performing a Hess Screen test and patient education animations.
1959 yilinda klinige elektroeman, Hess Screen, muscle trainer; 1960'lar da Elektro retinografi ; 1966 da A-Scan ve B Scan Ultrasonografi ; 1968 de aplanasyon tonometresi /tonografi aletlerini klinige katarak Turkiye'de birimlesmenin onculugunu yapmis; cok sevdigi , onem verdigi deneysel arastirmalari yapabilmek icin de genetik , bakteriyoloji , biyokimya ve goz patolojisi laboratuarlarini kurmustur.