These 10 animal facts will amaze you. Color blindness is most often a genetic visual deficiency that limits the colors that an individual can detect. Most people with this condition don't only see in black and white. The colors affected are usually limited to green and red, which often appear as shades of tan or brown.hese 10 animal facts will amaze you. Color blindness is most often a genetic visual deficiency that limits the colors that an individual can detect. Most people with this condition don't only see in black and white. The colors affected are usually limited to green and red, which often appear as shades of tan or brown.
The duration of the QT-interval varies dependent upon how fast the heart is beating, but in normal healthy people, when the heart is beating 60 beats per minute, it is between 350 and 440 milliseconds.
Normal range at rest is between 60-100 beats per minute (bpm). The basic way to calculate the rate is quite simple. You take the duration between two identical points of consecutive EKG waveforms such as the R-R duration. Take this duration and divide it into 60.