Gamers have reported perceiving objects outlined or glowing, similar to the visual effects in the video games. These seems to be fleeting and non-malignant visual experiences.
Interestingly, visual distortions of physical stimuli (e.g. objects or persons) does not seem to always occur randomly or in a generalized way, but with particular stimuli relevant for the individual.
These visual experiences appear to share similarities with visual illusions of an extra edge around objects, referred to as “Corona phenomenon”, as well as similarities with reports of seeing halos, borders or shiny rings on the contours of objects.
The corona phenomenon has been associated with migraine aura, side-effects of drug consumption and prolonged sensory deprivation.
Further readings
Ortiz de Gortari, A. B., & Griffiths, M. D. (2014). Altered Visual Perception in Game Transfer Phenomena: An Empirical Self-Report Study. International Journal of Human-Computer Interaction, 30(2), 95-105.
Podoll K, Robinson D (2001). Corona phenomenon as visual aura symptom in migraine. Cephalalgia. 21(7), 712-7.