A Field Observation of Display Placement Requirements for Presbyopic and Prepresbyopic Computer Users

Abstract

User-selected display placement for young computer users (prepresbyopes) and older computer users with presbyopia, wearing multifocal lens correction, has been observed in field settings, but not while both groups used the same display size or illumination technology. A field study was conducted to examine placement of an 18.5-inch, widescreen LCD display for prepresbyopes and presbyopes using multifocal lens correction. Both groups viewed the 18.5“ display for four days as they performed their usual computer tasks at their workstations. Multifocal wearers selected a display height that was lower than computer users who did not have presbyopia. As a result the eye-to-screen angle for presbyopes was significantly lower than prepresbyopes. The findings potentially affect proper design and selection of adjustable display supports. Measures of gross body posture and text size were also collected. Multifocal wearers did not choose seated postures different from prepresbyopes. Additionally, the majority of both groups viewed text at arc angles smaller than ANSI/HFES 100–2007 and ISO 9241–3 recommendations.

The vertical monitor position for presbyopic computer users with progressive lenses: how to reach clear vision and comfortable head posture

“…The present preferred gaze inclination of about 2 208 with a range from 2 108 to 2 308 corresponds to conclusions based on biomechanical modelling (Straker et al 2009) and resembles the finding of other recent studies (Allie, Purvis, and Kokot 2005, 2010Meinert, König, and Jaschinski 2013;Jaschinski et al 2015b). This range is in accordance with the average vertical zone of clear vision for general-purpose progressive lenses (Figure 1).…”

How to place the computer monitor: measurements of vertical zones of clear vision with presbyopic corrections

“…Within this range, the flexibility of the average user to choose a comfortable gaze inclination is limited: the eyes may adopt an individual vertical gaze inclination to the centre of the monitor within the range of approximately ‐10 to ‐30 degrees relative to the horizontal (average approximately ‐20 degrees). These gaze inclinations are in the same range as previous findings of visual and musculoskeletal research . The following rule of thumb can be suggested: for a conventional viewing distance of approximately 75 cm, the upper edge of the monitor should be at least approximately 15 cm below eye level, which corresponds to a gaze inclination of at least approximately ‐20 degrees to the centre of the screen (for a monitor height of approximately 30 cm).…”

“…These gaze inclinations are in the same range as previous findings of visual and musculoskeletal research. [22][23][24][25][26][27] The following rule of thumb can be suggested: for a conventional viewing distance of approximately 75 cm, the upper edge of the monitor should be at least approximately 15 cm below eye level, which corresponds to a gaze inclination of at least approximately -20 degrees to the centre of the screen (for a monitor height of approximately 30 cm). This rule of thumb serves only as a rough guide based on mean group data.…”

“…In fact, the following field studies yielded results that are compatible with the vertical zones of clear vision as measured with the inclined optometer. Allie and colleagues 26,27 conducted two office studies with freely adjustable monitor positions. 1.…”

Comparison of progressive addition lenses for general purpose and for computer vision: an office field study

“…Work‐related and ergonomic aspects play a role because the refractive lens profile is related to favourable viewing distances and vertical gaze angles at the workplace. When the monitor can be adjusted freely to the individual preference, the gaze inclination to the screen (Figure ) was found to be 7.7 degrees lower in users of multifocal lenses than in pre‐presbyopic users; however, in a more fixed high monitor position, general purpose PALs induce a higher muscular load in the neck with an upward inclination of the head, while this does not occur with computer vision PALs …”