This guide explains visual requirements for safe driving, covering mandatory eyesight testing for drivers under 65 and medical examinations every three years for those 65 and above. It details specific visual acuity standards including 6/12 vision in one eye for non-commercial drivers and both eyes for commercial drivers, acceptable color vision for traffic light recognition, and conditions that make driving unsafe including visual field defects from glaucoma or stroke, double vision, cataracts, diabetic eye disease, and macular degeneration.