a hand tool consisting of a handle fixed to a copper tip that is heated, electrically or in a flame, and used to melt and apply solder. Word Frequency. a pointed metal tool heated for use in melting and applying solder. More heat came from a small soldering iron which was slowly growing red at the side of the fire.
What is colour blindness? Colour (color) blindness (colour vision deficiency, or CVD) affects approximately 1 in 12 men (8%) and 1 in 200 women in the world. In Britain this means that there are approximately 2.7 million colour blind people (about 4.5% of the entire population), most of whom are male.
There are three basic variants of color blindness. Red/green color blindness is the most common deficiency, affecting 8% of Caucasian males and 0.5% of Caucasian females. The prevalence varies with culture.