There are several advantages to using tempered glass and it should be the only glass used in safety applications and applications that require a lot of temperature changes (such as freezing and heating). Tempered glass is 4-5 times stronger than regular glass.
A visual migraine is a temporary visual distortion that often begins with a small sparkling, shimmering area that slowly expands outward. The growing spot often has jagged, zig-zag edges. The visual symptoms typically last approximately 20-30 minutes and then completely resolve.
Other Visual Phenomena: 1  Ophthalmic Migraine (also called acephalgic migraine, migraine aura without headache, amigrainous migraine, isolated visual migraine, ocular and optical migraine) 2  Transient Visual Obscurations. 3  Rainbow Vision. 4  Abnormal Color Vision. 5  Distorted Vision. 6  Tunnel Vision. 7  Retinitis pigmentosa.