The Effects of LCD Anisotropy on the Visual Performance of Users of Different Ages

Objective: The present study examined the visual discrimination speed and accuracy while using an LCD and a CRT display. Background: LCDs have ergonomic advantages, but their main disadvantage is that they provide inconsistent photometric measures depending on the viewing angle (anisotropy). Method: Independent variables were screen type (LCD and CRT), viewing angle (0°, 11°, 41°, 50°, and 56°) and user's age (teenagers, young adults, and middle-aged adults). Dependent variables were speed and accuracy in a visual discrimination task and user's ratings. Results: The results corroborated the negative impact of LCD anisotropy. Visual discrimination times were by 7.6% slower when an LCD was used instead of a CRT. Performance differences increased with increasing viewing angle for both screens, but performance decrements were larger for the LCD. Young adults showed the best visual performance, as compared with teenagers and middle-aged adults. Effects of anisotropy were found for all age groups, although the performance of middle-aged adults was affected more when extended viewing angles were adopted. Conclusion: LCD anisotropy is a limiting factor for visual performance, especially in work settings where fast and accurate reactions are necessary. Application: The outcomes of this research allow ergonomic guidelines for electronic reading.

[1]  J. Jacko,et al.  The human-computer interaction handbook: fundamentals, evolving technologies and emerging applications , 2002 .

[2]  D. Maurer,et al.  Development of spatial and temporal vision during childhood , 1999, Vision Research.

[3]  T. Salthouse.  Adult cognition : an experimental psychology of human aging / Timothy A. Salthouse , 1982 .

[4]  Donald W. Kline,et al.  Aging and human visual function , 1983 .

[5]  Olaf Oehme,et al.  Visual displays , 2002 .

[6]  M Brüwer,et al.  Preferred vertical gaze direction and observation distance. , 1991, Ergonomics.

[7]  George K. Hung,et al.  Static vergence and accommodation: population norms and orthoptics effects , 1986, Documenta Ophthalmologica.

[8]  Frank Schieber,et al.  Vision and aging. , 2006 .

[9]  W Jaschinski-Kruza,et al.  Eyestrain in VDU Users: Viewing Distance and the Resting Position of Ocular Muscles , 1991, Human factors.

[10]  O. Heller,et al.  Hörfeldaudiometrie mit dem Verfahren der Kategorienunterteilung (KU) , 1985 .

[11]  J. Botwinick,et al.  Age changes in pupil size. , 1950, Journal of gerontology.

[12]  Martina Ziefle,et al.  Visual Costs of the Inhomogeneity of Luminance and Contrast by Viewing LCD-TFT Screens Off-Axis , 2003, International journal of occupational safety and ergonomics : JOSE.

[13]  J. Birren,et al.  Aging and speed of behavior: possible consequences for psychological functioning. , 1995, Annual review of psychology.

[14]  Gavriel Salvendy,et al.  Handbook of human factors. , 1987 .

[15]  G. Santucci,et al.  [Visual displays]. , 1981, L'Annee therapeutique et clinique en ophtalmologie.

[16]  Justin G. Hollands,et al.  LCD versus CRT Displays: Visual Search for Colored Symbols , 2001 .

[17]  Justin G. Hollands,et al.  LCD versus CRT Displays: A Comparison of Visual Search Performance for Colored Symbols , 2002, Hum. Factors.

[18]  Arthur D. Fisk,et al.  Handbook of human factors and the older adult , 1997 .

[19]  Justin G. Hollands,et al.  20.3: Visual Search Performance on LCD and CRT Displays: An Experimental Comparison , 2000 .