Intelligent sun shading glass changes its opacity according to ambient temperature. Two layers of glass sandwich a gel polymer which reacts to the surrounding temperature by changing its level of transparency. On a cool day, the glass is clear and has a high transmittance, allowing the sunlight to come in and warm the interior. On a hot bright day, when the temperature rises above a given value, the polymer within the glass will respond and begin to reduce transmittance. The higher the temperature rises, the more solar energy is blocked. Up to 70% of the sunlight is blocked outside (similar to the effect of a cloudy day). This can reduce the energy required for cooling by a great amount. The sun shading glass uses the available solar energy in a clever way and is suitable as a low carbon and energy saving material. The producer, Rightvary, is a high-tech enterprise involved in R&D, production and sales of exterior sun shading materials for buildings. The product works by temperature induction and has an operating range of 15oC—40oC. Various colours are possible and many common types of commercially available glass can be used. Applications include public buildings, sun room, glass shelters, curtain wall and greenhouses.