Patricia E. Bath, an ophthalmologist who took a special interest in combating preventable blindness in underserved populations and along the way became the first black female doctor to patent a medical invention, a laser device for treating cataracts, died on Thursday in San Francisco. She was 76. Dr. Bath was an educator and researcher as well as a physician. When she was just out of medical school, working as an intern at Harlem Hospital and then at an eye clinic at Columbia University, she noticed discrepancies in vision problems between the largely black patient population at Harlem and the largely white one at Columbia. Her observations led her to document that blindness was twice as prevalent among black people as among white people — findings that instilled in her a lifelong commitment to bringing quality eyecare to those who might not otherwise have access to it. Click here to read her obituary in The New York Times.