The exact causes remain unclear. Cataracts have been diagnosed and treated for thousands of years, though the methods to treat it have advanced considerably, nothing has been developed prevent cataracts. Though rare, some forms of cataracts are a result of blunt trauma to the eye or exposure to radiation. Medications such as steroids can cause cataracts after prolonged exposure. For most people, it is believed that exposure to ultraviolet light will speed the development. As with nearly every medical condition, smokers have higher incidence of cataracts. Even the person who manages to avoid every risk factor will likely develop cataracts at some point as a result of age. Symptoms of Cataracts Although people describe many different visual changes, several common themes have come to be recognized as the most frequent changes due to cataracts. Often time, a loss of clarity of colors will be the first symptoms. Later, patients often notice that sunlight or the lights from oncoming traffic at night produce a sever glare. Additionally, a frequent change in eyeglass prescription may signal the start of worsening cataracts.