measures the pupil size and response time. Whether you are a full-time physician or part-time assistant, they are an important item to carry at all times. These penlights are small and lightweight and comfortably fit inside a shirt pocket for easy access. Some also have pocket clips to help them remain in place and prevent damaging falls. You’ll also be able to enjoy ergonomic designs that make these items incredibly easy to hold and manipulate.  The light is easily activated when the clip on the pen is pressed. They focus light into a beam, making it easy to accurately view the inside of a person’s mouth or ears or study a person’s pupils