That is why most states required that children have a vision screening before they are enrolled in kindergarten. Even if you live in a state with no such requirement, the American Optometric Association recommends that all children, with or without any symptoms, get a comprehensive eye exam when they start school.
Kids need to start school ready to thrive in an educational environment, and even if a child's vision was normal a year ago, as children grow, their bodies change. Eyesight develops rapidly after birth, with focus and eye movement developing in the first 6 months of life. Initial exams are followed by a checkup at age 3, all usually done by a pediatrician. When children are school age, it's vital to again ensure that their vision is clear.
Public schools in the following states require an eye exam and/or a vision screening: Alabama, Alaska, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wyoming. Remember that guidelines can change, so always check with your child's school for its admission requirements.
Vision can change frequently early in life because a child's body adapts developmentally, so a child may have normal eyesight but not have 20/20 vision prior to starting kindergarten. Visual acuity, the accuracy of vision when measured by an eye chart, may still be maturing in a 5-year-old. A preschooler with 20/30 vision can have strong eyesight because it's likely that child's vision will develop naturally into 20/20 by first grade. And visual acuity isn't the only reason for exams. Eye charts can't tell the whole story. At the test, the vision screener will also confirm a child's eyes are able to work in tandem and keep their place when the child reads a line of print.
Although adults are accustomed to a variety of letters on an eye chart, pre-kindergarten screenings often use a chart with a tumbling "E." This is useful to test vision when children are not yet able to read, and allow them to communicate which direction the letter is facing without becoming confused about what letter is on the chart. A complete pre-kindergarten checkup will include a general physical exam of the eye, as well as eye charts with images, letters, or a tumbling "E." Comprehensive eye exams will confirm that all the elements of the eye are working together, so that the child to see clearly.
Amblyopia, or lazy eye, occurs when one eye doesn't develop properly. Because the stronger eye compensates, a child's weaker eye may never develop to its full capacity if amblyopia goes untreated. Permanent vision loss can result, because, as the child develops, the brain may adapt by disregarding the image coming from the weak eye. The condition is commonly discovered in children between the ages of 3 and 6, once they can cooperate with a vision screening, and an eye patch or glasses are used to help the ineffectual eye grow stronger. According to Dr. Hsueh, amblyopia is best treated by age 5 or 6, although studies have shown some success with older children.
Just as with adults, for children to get maximum visual efficiency, it's important for them to stay hydrated, eat a balanced diet, and develop good sleeping habits. Without overall health, a child can experience disruptions in normal vision and these interruptions can mirror eye concerns. If they lack key healthy habits, "children can have a hard time focusing and may have headaches or other issues that can mimic vision problems.