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.
1 Venus is sometimes called Earthâs sister planet. 2  This is because their size is very similar (there is only a 638 km different in diameter) and Venus has around 81% of Earthâs mass. 3  They are also similarly located with Venus being the closest planet to Earth. Venus is the closest planet to Earth. 2  When Venus is in line with Earth and the Sun, it is the closest planet to us, at an average distance of 41 million kilometers (25.5 million miles) away.