Youth and some adults have photoscreening refractions and hand-held auto refraction before cycloplegia refraction during new and follow up eye examinations. Vector math is applied to each refraction to determine how closely the hand-held "dry" devices match actual refraction.

A closeness-of-fit algorithm utilizing vector transformations of astigmatism is designed and applied to 50-years of clinical international refractive experience.

As a part of new and follow up comprehensive eye examinations, patients and parents consented to confirm the cycloplegic refraction to other portable refractive tools.

The ability of photoscreeners "2WIN" ("Adaptica," Padova italy), "PlusoptiX A12" (Nuremberg, Germany) and "Retinomax" (Righton, Tokyo, Japan) to match actual refraction is assessed utilizing the new algorithm.

This algorithm could then be applied to batches of donated spectacles distend by charitable organizations worldwide if portable auto refracting devices are employed.

Inclusion Criteria:

• Patient undergoing new or follow examination at pediatric eye and adult strabismus clinic Willing to undergo screening refractive device developmental delays included

Exclusion Criteria:

• Intraocular lens in place

children and adults attending pediatric ophthalmology and adult strabismus clinic

de-identified database shared on www.ABCD-Vision.org Website.

after study completed

open