Environmental Engineering Reference
In-Depth Information
(c)
Fig. 5. (a) Level of eyestrain symptom (b) Level of blurred vision symptoms (c) Level of dry
and irritated eyes symptoms
4.5 Analysis of the speed of the virtual objects motion
Different speeds of the virtual object motion in the VE were investigated. Statistical binomial
test (Table 5) shows that users suffers from eyestrain, blurred vision and dry and irritated eyes
when interacting with virtual objects at low and high speed of motion. This is because the eyes
are trying to focus on the virtual object in motion which requires good coordination with the
hand when performing task. Figures 6 (a), (b) and (c) shows the level of symptoms
experienced by the users. It can be seen that the speed of virtual object motion needs to be
considered as an attribute in designing of a VE. A higher speed of the virtual object motion is
better than a lower speed. This is because at higher speeds there is no effect on users whether
for eyestrain symptoms or dry and irritated eyes symptoms compared with lower speeds.
4.6 Analysis of the resolution of display
Many research have been conducted and have concluded that working with LCD screen is
much more comfortable compared to working with CRT screens (Alstrom, et al, 1992; Saito, et
al, 1993; Shieh,K.K., and Lin, C.C., 2000). This is contributed to the luminance contrast and
limited viewing angle of LCD screens (Snyder, 1988). Additionally, the TFT-LCD screen seems
to be the preferred technology by users for identifying letters on VDTs (Shieh, K.K. and Lin,
C.C.,2000). In the current research, statistical binomial test (Table 6) have found that eyestrain
and dry and irritated symptoms were experienced by users at three different resolution (high,
medium and low resolution) whilst dry and irritated eyes incidence were experienced by users