Cooling glasses

Very high purity fused silica glasses are made, which have negligible thermal expansion. Hence, they are suitable for making items of high accuracy such as space telescopes. Photochromatic (also called photochromic) glasses are those glasses that darken in sunlight. These are useful for making cooling glasses.

A loud implosion and a thick blanket of black smoke are what remained of the twin tower of Prime Trust Heights in Moulivakkam, which was demolished at 6.52 pm on Wednesday. […] "I have an umbrella, cooling glasses, binoculars, water bottle, and I am all set to take a selfie when the building comes down," said Ananth, a class 10 student.

Suddenly, Somu took his cooling glasses from his pocket and asked him to wear them and later, Ramu slowly managed to see. Somu advised Ramu on the necessity of wearing sun glasses during summer season.