Eyeglasses made of nylon were introduced in the late 1940s. Because of brittleness and other problems, eyeglass manufacturers switched to blended nylon (polyamides, co-polyamides and gliamides). Today's blended nylon frames are both strong and lightweight.
Venus is the closest size to Earth and is sometimes called Earth's sister planet.. Its diameter is 95% of Earth's but its mass is only 81% as much.
VENUS is the closest planet to Earth, and is the third brightest object in our sky after the sun and moon. Although it is similar to our planet in size, mass, and density, its surface environment is quite different. The atmosphere is made up of 96% carbon dioxide and small amounts of acids.