**3. Results**

174 Virtual Reality and Environments

H1: Colour of background has effect of visual symptoms among immersive

 H2: Virtual lighting has effect of visual symptoms among immersive environment users H3: Field of View (FOV) has effect of visual symptoms among immersive environment

 H4: Flow rate (FR) has effect of visual symptoms among immersive environment users H5: Speed of virtual object motion has effect of visual symptoms among immersive

H6: Resolution of display has effect of visual symptoms among immersive environment

H7: Contrast ratio has effect of visual symptoms among immersive environment users

The experiments were conducted at the ergonomic-virtual reality laboratory. A sitting position was adopted with the subject sitting at a distance of 15 – 25 cm from the back edge of the table to complete the task. The activity is to operate a virtual robot in the VE using an infrared mouse (wireless mouse) with the motion observed on the wide screen display.

The digital projector was positioned on a table 75 cm in height with an inclination angle of between 5o-10o with respect to the horizontal axis. The projector was connected to laptop with a display set to 1280 x 800 pixels. The distance from the front edge of the table or the digital projector to the center of the wide screen was 300 cm. The size of wide screen display is 170 cm in length and 155 cm in width. The bottom edge of wide screen display was measured at 94 cm above the floor. Prior to conducting the experiment, the subjects were

The subjects were provided with information describing the aims of the study and how the experiment will be conducted. Their health condition and past experience of sickness were also identified and their anthropometric data measured. The colour blind test was then conducted before proceeding to colour selection and the experiment. If a subject cannot complete the test, it means that the subject has some visual problems and is unable to

Prior to performing the experiment, subjects were trained on how to use the wireless mouse in order to operate the virtual robot in the VE to complete the virtual task. Heart rate and

In the experiment, subjects were exposed to the virtual environment to view and operate a virtual robot by using a wireless mouse; to pick up a virtual material in a rack and to put it on a conveyor and subsequently to also pick up a virtual product on the conveyor and store in another rack as shown in Fig. 1. The activity was performed for 10 minutes for each attributes and for every subject of the VE studied. All subjects were required to sit in an upright posture

made to adjust their seating positions to make them as comfortable as possible.

visual acuity was measured before and after the experiment.

The level of significance was set at α = 0.05 for all analyses.

**2.3 Experimental design and procedure** 

environment users

environment users

**2.3.1 Experimental design** 

**2.3.2 Experimental procedure** 

continue the experiment.

users

users
