While the development of cataracts differs for each patient, a cataract develops from the natural degradation of your lens as you age. In many cases, the lens loses its natural flexibility when a patient reaches the age of 40. This loss of flexibility reduces your ability to properly shift your vision from near, middle, to far distance. Most commonly, cataracts tend to gradually form as you age, slowly progressing over months and years before it dramatically affects your vision. While less common, traumatic cataracts result in rapid clouding of the eye lens and quickly occurring vision impairment.