Cataract

A 71-year-old woman presents to her primary care physician with visual changes. The patient has been seeing colored halos around lights for the past six months and has also noticed her vision has become progressively blurrier. Since symptom onset, she has not experienced any pain or conjunctival erythema. Past medical history is notable for type II diabetes mellitus, hypertension, and asthma. She is currently retired but formerly worked as a national park ranger. Temperature is 37.7°C (99.9°F), blood pressure is 151/83 mmHg, and pulse is 76/min. Visual acuity is 20/20 in the right eye and 20/70 in the left eye. A slit-lamp examination is shown below. Which of the following is the most common risk factor for the development of this patient’s condition?
 
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