Supplemental Testing

Color vision — Ishihara pseudoisochromatic plates screen red-green congenital deficiency; the Farnsworth D-15 arranges hues and also catches blue-yellow and acquired defects. Test each eye separately under good lighting, with correction on.

Stereopsis — Titmus fly/circles or random-dot tests quantify binocular depth perception in seconds of arc; gross stereo confirms both eyes are working together.

Pachymetry — ultrasonic or optical corneal thickness; thin corneas under-read applanation IOP and independently raise glaucoma risk.

Glare and contrast sensitivity — cataract patients with good chart acuity but real-world complaints often fail glare testing; contrast sensitivity catches functional loss the Snellen chart misses.

Schirmer and tear testing — strips quantify aqueous tear production for dry-eye workups; note anesthetic vs no-anesthetic protocol on the chart.