The bill states, "Seventy percent of our youthful offenders and 90 percent of our adult offenders are known to have one or more of these vision problems that went undiagnosed in their developing years."

State law requires general vision screenings in schools every third year, starting with the enrollment of the child in school and ending at the completion of eighth grade. The "big E chart," formally known as the Snellen chart, is often the primary test included in the screenings, administered by school nurses, pediatricians, teachers or volunteers.

But according to some eye care professionals, the school exams often miss vision problems in children. Some of those physicians are lobbying for the state to mandate comprehensive eye exams in children by professionals.

The American Optometric Association reports that 25 percent of American children have vision problems significant enough to potentially prevent them from succeeding in school. In fact, 60 percent of children who are identified as "problem learners" have undetected vision problems.

"Young kids don't know enough to complain that their eyes hurt when they read, so they just act up," says Dr. Eileen Polhemus, a Los Gatos optometrist who specializes in pediatric optometry. "We want to catch vision problems early, so kids have their best chance of doing well in school."

Only about 14 percent of children receive an eye exam before entering school. To boost this number, many states have passed laws requiring that children receive eye exams before kindergarten.

California, however, has not done so.

The most recent census data indicates that 6.5 million state residents do not have medical insurance. Proposing comprehensive state-mandated eye exams raises questions about who will pay for the eye exams and subsequent corrective measures.

"California is one of the last states to mandate eye exams for students," Polhemus says. "Unfortunately, the biggest reason is financial."

Dr. Richard Bensinger, a Seattle-based opthamologist, is the spokesman for the American Academy of Opthamology.

While Bensinger advises parents to take their children for general eye exams, he says the state making them mandatory is unnecessary.

"The vast majority of visual defects are going to get picked up by two social forces"—mothers and pediatricians, Bensinger says. He adds that schools' vision screenings tend to reveal problems that would require a visit to a specialist.

Parents can look for symptoms that may indicate if their child has a vision problem. If a child loses his or her place while reading, holds reading material closer or farther than normal, has headaches or turns or tilts the head to use one eye only, chances are the child has vision problems.

"Conditions such as strabismum and amblyopia—what is commonly referred to as a 'lazy eye'—need to be corrected by the age 5," Polhemus says. "When one eye doesn't see as well as the other, the nerve connection for the lazy eye is never made."

Bensinger says, however, that the condition actually becomes permanent at the age of 7—after the student's first school exam—and is detectable by the mandated vision screenings.

Bensinger recommends a simple test that parents can perform: take a closer look at photographs of their children. The red-eye syndrome in pictures comes from the lens reflecting color in the back of the eye.

"If you see red-eye most of the time in both eyes at the same time," he says, the child does not have lazy eye.

Gloria I. Wang contributed to this story.