Diagnostic Eye Instruments Vocabulary

Vocabulary flashcards covering diagnostic eye instruments, their definitions, inventors, and clinical uses based on the lecture notes.

Keratometer (Ophthalmometer)

An instrument invented by Hermann von Helmholtz in 1851 that measures the curvature of the anterior surface of the cornea, used for assessing astigmatism, fitting contact lenses, and evaluating tear film via NIBUT.

Hermann von Helmholtz

The inventor who created the keratometer (ophthalmometer) in 1851.

NIBUT

Non-Invasive Tear Break-Up Time, a method used to assess tear film quality using a keratometer.

Ophthalmoscope

A flashlight-sized instrument with multiple lenses magnifying up to 15 times, used via direct or indirect methods to inspect the fundus background, optic disc, and macula, and detect ocular pathology.

Retinoscope

A diagnostic instrument that shines a streak of light into the patient's eye to observe the retinal reflex, providing an objective measurement of refractive error.

Phoropter

An instrument containing various lenses used during sight testing to measure refractive error, phorias, duction, heterophorias, vergence, and accommodative functions.

Heterophoria

The natural resting position of the eyes, which can be evaluated using a phoropter.

PD Meter (Pupilometer)

A device used to digitally measure the distance between the centers of the pupils in each eye to ensure accurate placement of eyeglass prescriptions.

Slitlamp Biomicroscope

An instrument equipped with a high-intensity light source that shines a thin sheet of light into the eye across a wide range of magnifications to examine both anterior and posterior segments.

Tonometer

An instrument used to measure intraocular pressure (IOP), essential for evaluating patients at risk for glaucoma.

Intraocular Pressure (IOP)

The fluid pressure inside the eye, measured by a tonometer in the diagnostic evaluation of glaucoma risk.

Snellen Chart

A chart developed in 1862 by Dutch ophthalmologist Hermann Snellen used to measure visual acuity.

Hermann Snellen

The Dutch ophthalmologist who developed the Snellen chart for measuring visual acuity in 1862.

Autorefractometer

A computer-controlled automated refractor that provides an objective measurement of a person's refractive error and prescription for glasses or contact lenses.

Lensometer

An instrument (also known as a focimeter or vertometer) used to verify eyeglass prescriptions, align and mark uncut lenses, and confirm correct lens mounting in spectacle frames.

Trial Lens Set

A collection of loose lenses and accessories used during an ocular examination to test and refine a spectacle prescription.

Amsler Grid Chart

A diagnostic grid chart with a central dot used during eye examinations to test central visual fields and detect macular irregularities.

Ishihara Plates

Pseudoisochromatic dot-patterned plates used during ocular examinations to screen for color vision deficiency.

RAF Rule

A measurement device used in binocular vision testing to evaluate convergence and accommodation.

Maddox Wing

A hand-held binocular testing instrument used to measure heterophoria at near distances.

Corneal Topographer

An advanced diagnostic device used in contact lens examination to map the curvature and surface profile of the cornea.

Tangent Screen

A device used during ocular visual field assessment to evaluate central vision and blind spots.

Automated Perimeter

An instrument used to measure and analyze a patient's visual field automatically.