Cybersickness is a term to describe motion sickness experienced by users in Virtual Reality systems. In a typical Virtual Environment, users often view moving scenes while they remain physically stationary. Examples of cybersickness symptoms include nausea, eye strain, dizziness, headache.

Virtual Reality System(VRS) is a computer-generated environment which can be used to simulated different real situation. Various kind of equipments are used, such as Head-mounted Display (HMD) and cybergloves. VRS users could have feeling as if they were really in the Virtual Environment (VE). They can even interact with the virtual objects. E.g. pilot training and entertainment. In this, pilot feels like sitting in the real cockpit.

A troublesome problem with current virtual environment (VE) technology is that some users feel parallel symptoms of classical motion sickness both during and after the VE experience. This type of sickness is called cybersickness. Unfortunately, there are many factors that can cause cybersickness. Till now, there is no foolproof method for eliminating the problem.