Sometimes vision problems develop over time or they are so subtle that they have gone previously undiagnosed.  Often a student can have vision impairment, but it may have gone unnoticed.  The student is often the last one to recognize or report a loss in vision unless it has deteriorated.  If the vision impairment remains undetected, it can result in the student facing a substantial educational disadvantage because of adverse effects on the student’s academic, communication, and social development.  This can interfere with a student’s ability to reach full potential.  On a medical note, if the vision problem is left undetected and untreated, it can cause permanent loss of vision and the long-term consequences can be serious in terms of quality of life. zenith labs vision 20 review