Photometric compliance of standard and digital infant acuity tests

Amblyopia or “lazy eye” affects approximately 2–5% of the general population in the UK[1]. Treatment must be started as early as possible as it is less effective after age 8[2]. The current gold standards for infant acuity testing are based on printed cardboard targets (‘standard tests’) and have been in place for almost 35 years[3]. In spite of this, no national nor international standard criteria are in place to quality assure them. Electronic platforms show promise to replace card-based tests[4]. However, the fast-changing nature and photometric differences across manufacturers of electronic devices makes them potentially inaccurate when used for visual testing[5]. This work studied the photometric compliance of three standard tests (Teller cards, Keeler cards, Lea Paddles) and four electronic displays (phone, tablet, laptop and 4k monitor).