Neuroophthalmology from the Perspective of anAnterior Segment Surgeon

Gerhard K. Lang

Department of OphthalmologyUniversity of Ulm

Neuroophthalmology from the Perspective of anAnterior Segment Surgeon

Gerhard K. Lang

Department of OphthalmologyUniversity of Ulm

Eye -and Brain - Entertainment

„Do not trust your eyes!“

REM

Optical Illusions and

visual Phenomena:

Illusion and Reality

Salvadore Dali 1904-89

Gala looking into the Mediterranean Sea

Effect:“Lincoln Illusion“ („block masking“) Harmon LD & Julesz B (1973). Masking in visual recognition: Effects of two-dimensional filtered noise. Science 180:1194–1197

Ambiguous pictures

Reversible goblet – Edgar J. Rubin

Reversible goblet – Edgar J. Rubin

Ambiguous pictures

Effect: rival-schemata ambiguity

Rabbit and Duck

Ambiguous pictures

Effect: rival-schemata ambiguity

Effect: rival-schemata ambiguity

Effect: rival-schemata ambiguity

Sigmund Freud, Neurologist, 1856-1939

Kanisza figure (Gaetano Kanisza)

Effect: subjective or illusory contours

Congnitive- / Gestalt Field

Effect: subjective or illusory contours

Effect: subjective or illusory contours

Size Illusions

Original: Müller-Lyer Illusion

St Michael's Hill, Bristol, England

Effect: „Bristol Café wall Illusion“

This illusion demonstrates the effect of some simple image processing occurring at the retina combined with some complex processing in the cortical cells of the striate cortex.

Geometric- & Angle Illusion

Gregory RL & Heard P (1979) Border locking and the Café Wall illusion. Perception 8:365–380

The apparent tilt of the mortar linesis caused by orientation-sensitive simple cells in the striate cortex.

The cushion Illusion

This drawing consists solely of rectangles and squares, set straight and true; the curvature is all in your mind.

Akiyoshi Kitaoka 1998

Petersdom, Fassade von C. Maderno 1607-1612

Fraser`s Spiral („Twisted Cord Illusion“)

Fraser J (1908) A New Visual Illusion of Direction.Brit J Psych 2:307-320

Drawing hands, Tekenen – M.C. EscherMaurits Cornelius Escher, Niederlande 1898-1972The magic mirror of M.C. Escher

Effect: Impossible objects

BelvédèreM.C. Escher 1958

The Pool

David MacDonald

The Terrace

David MacDonald

Pergola, Istvan Orosz, Hungary 1951

www.utiz.net

Hidden Images

Worth1000.com

„The Face in the Beans“

Furitsu (2002) photoshop contestWorth1000.com Effect: „one shot learning“

Dallenbach`s figure

Dallenbach`s figure

Dallenbach`s figure

Adelson`s „Checker-shadow illusion“

Adelson EH (1993)Perceptual organization andthe judgment of brightness.Science 262:2042-2044

Luminance & Contrast

Hermann Grid Illusion Luminance & Contrast

Hermann L (1870) Eine Erscheinung simultanen Contrastes. Pflügers Archiv für die gesamte Physiologie 3:13–15

Scintillating Grid

Schrauf M, Lingelbach B, Wist E.(1997) The scintillating grid illusion. Vision Res 37:1033-1038

Luminance & Contrast

Rotating Snake Illusion

Kitaoka A, Ashida H (2003) Phenomenal characteristics of the peripheral drift illusion.VISION 15:261-262

Effect: Illusory motion

Enigma

This image „The Enigma“ is by Isia Leviant (1984)

Effect: Illusory visual motion

final test

10 seconds concentration

Where is the giraffe ?

Department of Ophthalmology

Thank you for your

attention !

City Center of Ulm

World Ophthalmology Congress6 –10 June 2010Berlin Germany

www.woc2010.de