Computers are used everywhere from home to work these days, thus the effects on the visual system will be more noticeable every day. Problems associated with Computer usage are generally known as the Computer vision syndrome (CVS).These problems include eye fatigue, irritation, redness, blurred vision and dry eye. All of these problems have adverse effects on individuals in the long term and reduce the efficiency and quality of workers. CVS is due to various display characteristics such as screen brightness, high brightness in the workplace, screen refresh rate, radiation, reduced rate of blinking, large eye surface prone to dryness and accommodation effort for close work. Treatment requires a multidirectional approach such as adjustment of the workstation. Proper lighting, anti-glare filters, ergonomic positioning of the monitor and regular work breaks may help improve visual comfort. Lubricating eye drops and special Computer glasses help relieve ocular surface related symptoms. Also the treatment of this syndrome especially in the early stages has successful result, but users that do not know about this problems, tolerate a lot of complications.

With the rapid emergence of 3D applications and virtual environments in Computer systems; the need for a new type of interaction device arises. This is because the traditional devices such as mouse, keyboard, and joystick become inefficient and cumbersome within these virtual environments. In other words, evolution of user interfaces shapes the change in the Human-Computer Interaction (HCI). Intuitive and naturalness characteristics of “Hand Gestures” in the HCI have been the driving force and motivation to develop an interaction device which can replace current unwieldy tools. A survey on the methods of analyzing, modeling and recognizing hand gestures in the context of the HCI is provided in this paper. Taxonomy of the different algorithms based on the applications that they have been developed for and the approaches that they have used to represent gestures is presented. In addition, direction of future developments is discussed.