Last summer, a record-setting, five-day heat wave scorched Chicago, making headlines nationwide not just because of the sizzling temperatures — as high as 106 degrees Farenheit — but because older people died by the hundreds. By the time the heat wave was over, there had been more than 700 “extra” deaths, numbers so shocking that researchers from the city, state and the federal Centers for Disease Control and Prevention began poring over the data, searching for common denominators among people who died and those who did not.

After 33 years in the rough and tumble of Cambridge politics, including several stints as mayor, Walter Sullivan, 73, has developed a new — albeit unwanted — preoccupation during retirement: eye troubles.

In fact, there are four major vision problems that often plague older people — cataracts, glaucoma, macular degeneration and diabetic retinopathy — and Sullivan has them all.

Catherine Wright, 61, a retired telephone operator from Quincy who cheerfully admits she wore “fancy high heels” for years, sat propped up, admiring her podiatrist’s handiwork.