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.
These planets can be divided into terrestrial planets (Mercury, Venus, Earth, and Mars) and gaseous planets (Jupiter, Saturn, Uranus, and Neptune). The smallest planet is Mercury, which is closest to the sun. Venus is the second from the sun. It is similar to Earth in size and mass, but it is so hot, that lead would melt on its surface. The third from the sun is Earth. Its distance from the sun allows it to have liquid water and an atmosphere suitable for life.