Can one person still make a difference? The two-hour special “Rx for Survival: The Heroes” (8 p.m., PBS, check local listings) profiles doctors, health workers and ordinary people who applied simple solutions to complex public-health problems.

In the 1970s, a Baltimore eye doctor learned of the problem of night blindness affecting millions of people in the developing world. He theorized that a simple diet of rice, devoid of any natural source of vitamin A, could be the culprit. When given the vitamin, stricken children saw dramatic and near-immediate improvements in their sight. To his surprise, he later learned that children receiving a simple 2-cent dose of the vitamin were living longer and avoiding many infectious diseases.

Today, more than 70 countries have embraced his simple idea, resulting in the prevention of hundreds of thousands of needless deaths.

“Rx,” narrated by Brad Pitt, also looks at a couple of British motorcycle enthusiasts who helped African villages repair and maintain two-wheeled ambulances; an engineer dedicated to bringing clean water to a Ugandan village; a pair of doctors fighting tuberculosis in Peru; and a business-led campaign to save the people of Botswana from AIDS.

¢ Shows with uncertain futures always have the most interesting season finales. “George Lopez” (7 p.m., ABC) wraps up its year with the news that the plant has been relocated to Mexico. It remains to be seen whether only its fictional characters are set to lose their jobs.

Tonight’s other highlights

¢ Contestants race through Italy and Greece in search of a missing half of a Da Vinci masterpiece on “Amazing Race 9” (7 p.m., CBS).

¢ Howie Mandel hosts “Deal or No Deal” (7 p.m., NBC).

¢ It will take a solid hour to find out the results on “American Idol” (7:30 p.m., Fox).

¢ Ricky feels pressured on “Heist” (8 p.m., NBC).

¢ A rescue signal causes dissension on “Lost” (8 p.m., ABC).

¢ A would-be superhero is slain during a daring deed on “CSI: NY” (9 p.m., CBS).

¢ A rogue officer blackmails the prosecutor’s office on “Law & Order” (9 p.m., NBC).

¢ Five friends from a rehab center are murdered on “The Evidence” (9 p.m., ABC).