Simulated Impairment of Contrast Sensitivity: Performance and Gaze Behavior during Locomotion through a Built Environment

Abstract

The results for the simple route suggest ballistic strategies: the participant appraises the scene and follows a more or less predetermined path. For the complex route, CS impairment appears to adversely affect information processing and locomotion. The results have implications for the design of built environments, especially with regard to the safety of visually impaired occupants during emergency scenarios.

Functional Assessment of Head???Eye Coordination During Vehicle Operation

“…15 Moreover, the head-mounted cameras add significant mass to the head (300-g Vision 2000; 450-g iView X), which may impact operator behavior. Commercial VOG systems incorporating a scene camera to study gaze patterns have recently been used in flight simulator studies 28 and for monitoring the gaze of pedestrians crossing an intersection 29 (recording images to VCRs in the subject's backpack) and walking through a complex indoor environment 30 (with a 30-m umbilical cable). An often neglected aspect of viewing behavior while driving is movement of the head.…”

Eye Movements in Patients with Glaucoma When Viewing Images of Everyday Scenes

“…The link between eye movements and visual functioning has already received some clinical interest in amblyopia (Kanonidou et al, 2010), retinitis pigmentosa (Turano et al, 2001) and age-related macular degeneration (AMD) (Bullimore and Bailey, 1995). Individuals with contrast sensitivity loss were also found to produce abnormal eye movement behaviour as they manoeuvred complex routes through their natural environment (Vivekananda-Schmidt et al, 2004). Furthermore, the potential of such eye movement behaviour research with regards to the development of future low-vision rehabilitation strategies is beginning to be recognised .…”

The effects of temporal pressure on obstacle negotiation and gaze behaviour in young adults with simulated vision loss

“…Individuals with normal vision adopted a more cautious obstacle crossing strategy in anxiety inducing situations (i.e., higher clearance of the lead foot and a slower clearance of the lead and trail foot) 38 , contacted the obstacle less often 39 , and looked down more frequently and for longer when performing an obstacle course 26,32,38,39 . Similar adaptations in adaptive gait 8–12 and gaze behaviour 13,14 were observed in individuals with (simulated) cataract/blur when navigating through the environment without time pressure. However, it is currently unknown how individuals with visual impairment will behave in anxiety inducing situations (simulated through increased time pressure) and whether this behaviour is different from individuals with normal vision.…”

“…In addition, peripheral visual information is utilised for the online “fine tuning” of gait by providing exproprioceptive information (i.e., position of the lower limbs relative to the environment) 2,6,7 . Individuals with refractive error or cataract adapt their locomotion 8–12 and gaze 13,14 to safely navigate through the environment. Importantly, in all the aforementioned literature, gaze behaviour and adaptive gait were assessed when individuals were temporally unconstrained.…”

“…The higher anxiety levels in individuals with vision loss 40,41 , accompanied by a more conscious control of locomotion 46 , likely increase the cognitive load and require adaptations in locomotion 8–12 and gaze behaviour 13,14 to safely navigate through the environment. To illustrate, individuals with (simulated) cataract walked slower 8,10–14 , adopted a more cautious gait (i.e., a higher and slower clearance of the lead foot over the obstacle 9 and an increased toe clearance when ascending a step 8 ).…”