Validation of an iPad test of letter contrast sensitivity.

Purpose: An iPad-based letter contrast sensitivity test was developed (ridgevue.com) consisting of two letters on each page of an iBook. The contrast decreases from 80% (logCS = 0.

Fixation stability and scotoma mapping for patients with low vision.

Purpose: To develop a simplified device that performs fundus perimetry techniques such as fixation mapping and kinetic perimetry.

Methods: We added visual stimulation to a near-infrared retinal imager, the laser scanning digital camera (LSDC). This device uses slit scanning illumination combined with a two-dimensional CMOS (complementary metal oxide semiconductor) detector, with continuous viewing of the retina.