APD Tester™ is a patented portable diagnostic device primarily designed for the clinical evaluation of pupils. The Tester is used for A) evaluation of pupillary reactions, B) diagnosis of corneal lesions, and contact lens evaluations. This version features adjustable LED Lights.

Relative afferent pupillary defect (RAPD, also known as Marcus Gunn Pupil) can be difficult to detect. Further, dark irides and sluggish pupils are often challenging to examine. The APD Tester illuminates and magnifies the eye, so small contractions in the collarette of the iris are readily seen. In other patients, post-surgical or post-traumatic pupils can show reflexes to light in a small sector or iris. These can also be detected using the APD Tester which readily shows sectoral iris constrictions.