Teller Acuity Cards
Also written as: TAC — Teller Acuity Cards
A preferential looking test using grating stimuli to assess visual acuity in infants and non-verbal children.
Full Definition
Teller Acuity Cards utilize the preferential looking technique to measure grating acuity in young children who cannot perform standard letter charts. Each card contains a square wave grating on one side and a uniform gray field on the other, with gratings of decreasing spatial frequency. The examiner observes the child's preferential looking behavior through a central peephole to determine the finest grating the child can detect. Results are expressed in cycles per degree and can be converted to Snellen equivalents. The test provides reliable acuity measurements from 2 months of age and is particularly valuable for detecting significant vision differences between eyes in pre-verbal children.
Usage
Usage note: Results should be documented in cycles per degree with Snellen equivalent notation when applicable.
In Context
- "Teller Acuity Cards revealed 20/200 equivalent vision in the right eye of this 8-month-old infant." — Pediatric vision assessment
- "Preferential looking testing with TAC demonstrated symmetric grating acuity between both eyes." — Amblyopia screening report