Visual Acuity Tests in Pediatric Optometry

Minimum Visible Acuity

Refers to the smallest object or detail that the human eye can detect. Also known as Detection Acuity or Minimum Detectable Acuity

Minimum Recognizable Acuity

Describes the ability to identify or recognize a specific feature, such as a letter or symbol. Also known was Recognition Acuity

Minimum Resolvable Acuity

Refers to the smallest change in a visual feature that a person can detect. Also known as Resolution Acuity

Minimum Discriminable Acuity

Describes the ability of the visual system to distinguish between two closely spaced objects or the finest detail within an object. Also known as Localization Acuity

Optokinetic Nystagmus (OKN) Test

A test that assesses visual acuity by observing reflexive eye movements in response to a moving pattern such as a drum or computer screen displaying moving stripes.

Sheridan-Gardiner Ball Test

Assesses visual acuity by presenting colored balls of different sizes for the child to identify.

Cardiff Acuity Test

Utilizes recognizable pictures (house, fish, car, etc.) positioned on one half of the card, with the other half being blank to measure acuity.

LEA Grating Acuity Test

Measures the ability to detect or discriminate the orientation of grating patterns (alternating black and white lines) at different spatial frequencies. In discrimination tests, the child is asked to indicate the direction/orientation of the lines.

Teller Acuity Cards

Involves showing cards with black and white stripes (gratings) of varying widths to observe the child's ability to detect and determine the finest gating.

Preferential Looking Test (PL)

A method where infants are presented with two stimulus fields, one with pattern and one plain.

Forced-Choice Preferential Looking Test (FPL)

Requires infants to make a specific choice between two or more stimuli.

LEA Symbol Chart

A visual acuity test using simple shapes suitable for young children unfamiliar with letters.

HOTV Chart

A test using letters for children to match with a response card to determine visual acuity.

Broken Wheel Acuity Cards

Involves identifying the direction of a gap in a representation of a wheel to assess visual acuity.

Tumbling E

A test presenting the letter 'E' in various orientations for the child to identify direction.

Snellen Chart

A traditional visual acuity test using letters of varying sizes.

LogMAR Chart

A standardized visual acuity chart that provides a more precise measurement of visual acuity.

Bailey-Lovie Chart

The first LogMAR chart designed for clinical use in measuring visual acuity.

ETDRS Chart

A visual acuity test chart used primarily in clinical trials for diabetic retinopathy.

Catford Drum Test, Candy Bead Test

Test examples of Minimum Visible Acuity

Landolt C, Teller Acuity Charts, Tumbling E

Test examples of Minimum Resolvable Acuity

Snellen Chart, LogMAR Chart, Lea Symbols

Test examples of Minimum Recognizable Acuity

Vernier Acuity (Hyperacuity)

Test examples of Minimum Discriminable Acuity