A pilot study (O'Neil J.W., et al 2005 unpublished) suggested lay screeners using this an early version of this prototype vision screening software on laptop computers achieved similar positive and negative predictive value results to a certified ophthalmic technician using a professional grade M&S vision tester. Positive predictive values for clinically significant visual disorders were 54% for M&S and 52% for VisionQuest 20/20 respectively. Negative predictive values were identical at 97% for each screening method. VisionQuest 20/20 appears to have potential for use as a vision screener for schoolchildren and may allow more children to be reached than manual vision screening or other methods by relying on lay personnel already available in schools rather than certified vision screeners or eye professionals to perform screenings. Additional benefits include use of computers already available in schools with the potential to simplify vision screening logistics and reduce costs. Independent validity testing is essential before initiating large scale community vision screenings with this new vision screening software. The primary aim of the current study is to validate VisionQuest 20/20 screening software by assessing its ability to screen for threshold visual acuities as compared to an exact visual acuity obtained with the EVA tester using ETDRS optotypes. The secondary aim of the current study is to evaluate the ability of VisionQuest 20/20 software to detect the presence or absence of clinically significant vision disorders in children as compared to a professional eye examination by a pediatric ophthalmologist.