Nowadays contact lenses are a very common way of vision correction. To be used successfully, they must meet a number of conditions. This article describes studies on the influence of environmental factors such as low temperature (4°C), high temperature (60°C), various fluids (simulated tear fluid (STF), physiological saline, multi-purpose contact lens solution) and ultraviolet radiation on the properties (wettability, dehydration, UV-vis transmission, surface structure/ microstructure) of 3rd generation silicone hydrogel contact lenses. Contact angle measurement device, gravimetric method (measurement of dehydration), UV-vis spectrophotometry, ATR spectroscopy and SEM microscopy were used during the research. The results showed that environmental factors can influence some features of comfilcon A contact lenses. The reduction of contact lens water content, being the result of a long-term storage at high temperature, might cause changes in their elasticity, thereby sense of discomfort for the user, while storage in physiological saline causes slight decrease in visible light transmission. What is more, the temperature and fluids used for storage of silicone hydrogel contact lenses, as well as ultraviolet radiation affect the microstructure of analysed lenses.