In order to tell if your glass is tempered you should check the original packaging. Companies will specify if it is safe for the microwave and/or freezer. If you do not have the original packaging it is best to contact the company directly.
In a reachâgrasp task for targets within the binocular visual field, subjects switched between left and right eye dominance depending on horizontal gaze angle. On average, ocular dominance switched at gaze angles of only 15.5Â° off center.
horizontal field of view = 2 atan(0.5 width / focallength) where width is the horizontal width of the sensor (projection plane). So for example, for a 35mm film (frame is 24mm x 36mm), and a 20mm (focal length) lens, the horizontal aperture would be almost 84 degrees (vertical aperture of 62 degrees).