Traditional eye care is limited to what happens in front of the retina,"" say optometrists Seiderman and Marcus. Your sight is tested by reading the eye chart, and glasses are prescribed for refractive errors and astigmatism. With age comes a stiffening of the lens, making it hard for muscles to control its shape, and glasses again are prescribed. But what about those muscles? The authors, who describe themselves as ""developmental optometrists,"" are concerned with the normal course of development, in which infant eyes learn to focus and track, to converge in forming binocular images, and acquire visual-motor coordination and skills. These are developmental milestones that depend on nervous-system maturation and normal use of the eyes. But ""normal use"" becomes a problem for those with strabismus (cross-eye) or amblyopia (lazy eye), which can result in blurred or double vision, headaches, clumsiness, and sometimes leads to shutting out signals from the weaker eye so that vision becomes monocular. ""Vision therapy,"" the authors explain, uses a variety of instruments to train the eye-controlling muscles to correct visual defects. Not surprisingly, the doctors provide numerous case reports of successful rehabilitation. They suggest that schools need more than the ""E"" chart--they need vision consultants who will check out visual skills, especially in children having learning problems. One (Marcus) is also sports vision consultant for the US Olympic Team, and the chapter on sports vision is especially interesting in its reports of how great athletes use their eyes, and of the importance of ""centering."" Other topics covered include VDT problems, instruments that may help correct myopia, nutritional requirements for eye health, vision and juvenile delinquency. Not the answer to all visual problems (like dyslexia), but information and practical lips worth considering.