CLEVELAND -- Parents debate over whether it's best for their teenagers to learn about human sexuality at school or at home.

But while they are discussing, kids are learning a lot from another source -- the Internet and pornographic Web sites, television station WEWS reported.

There are an estimated 1 million porn sites, which are often easy to find.

According to the Kaiser Family Foundation, 70 percent of 15- to 17-year-old boys have visited a pornographic Web site.

"I'm hanging around kids my age, they all pretty much get their fair share of that stuff, I would say daily," said a 16-year-old, who did not want to be identified.

The National Institute of Health is studying the long-term effects of porn on young adults.

"It has the potential for teenagers to really mess up what their attitudes are about sexuality and really mess up relationships," said clinical psychologist Paul Schenck.

Counselors say during the impressionable years, teens may learn to view women as sex objects, extreme sex seems normal, and later, porn becomes part of their sexuality.

"So that then in their adult life, if they're wanting to get turned on, they know right where to go," said Schenck. "The brain know exactly what kind of images to pull up, and it can be very, very hard to change that, to alter that."

He recommends parents use site-blocking software and keep their computers in a busy place, such as the living room or the den.

Experts say it's a mistake to take this subject lightly -- the quantity, accessibility and graphic nature of the porn makes it much more likely it can become an addiction for a teen.