NBEO Part III key terms

The patient's own words describing the main reason for the visit, recorded verbatim and used to focus the examination and history-taking.

A chronological account of the current problem covering onset, duration, severity, provoking factors, associated symptoms, and prior treatment attempts.

A structured screening of body systems and ocular symptoms not yet mentioned, used to uncover relevant disease the patient did not volunteer.

A measurement of distance visual resolution expressed as a fraction, where the numerator is the test distance and the denominator the distance at which a standard letter subtends five minutes of arc.

The sharpest acuity obtainable with the patient's optimal refractive correction in place, used as the baseline for comparing future change.

A quick screening maneuver in which a small aperture is placed before the eye; improvement of acuity suggests uncorrected refractive error rather than disease.

A lens with equal plus and minus cylinder power at right angles, flipped before the eye to refine cylinder axis and power during subjective refraction.

A red-green comparison used to check spherical endpoint, relying on chromatic aberration so that green clarity indicates over-minus and red clarity indicates under-minus correction.

The final lens power at which further change no longer improves acuity, balancing maximum plus with best vision for comfortable distance and near focus.

An objective test in which each eye is alternately occluded while the uncovered eye is watched for movement, revealing manifest and latent strabismus and its direction.

A corneal light reflex test estimating ocular alignment by noting whether the reflex sits centered or displaced from the pupil in each eye.

Binocular depth perception produced by small horizontal disparities between the two retinal images, tested with polarized or vectographic targets to confirm sensory fusion.

A dissociating test using red-green goggles and four lights to assess fusion, suppression, and diplopia at distance and near.

Magnified, illuminated examination of the anterior and posterior segments by directing a narrow or broad light beam at varied angles to reveal depth and transparency.

A thin slit beam directed at the cornea to create a cross-sectional view, allowing the examiner to judge thickness, depth, and location of lesions.

A technique in which light is placed on the limbus so it travels through the cornea by total internal reflection, highlighting subtle opacities and edema.

Standardized ordinal scales, such as Efron or traditional 0 to 4 grading, used to record the severity of findings like injection, edema, or staining consistently.

A head-mounted or handheld condensing lens method giving a wide, inverted, and laterally reversed view of the fundus, useful for peripheral retinal screening.

Manual indentation of the sclera during peripheral fundus viewing to bring the ora serrata and far peripheral retina into view, mainly to detect tears.

Enlargement of the central excavation of the optic nerve head relative to the disc rim, a key structural sign monitored in glaucoma.

Measurement of intraocular pressure by flattening a fixed corneal area with a calibrated prism, requiring topical anesthesia and fluorescein and affected by corneal thickness.

Corneal thickness measured by pachymetry, used to interpret applanation readings because thinner corneas tend to understate and thicker corneas overstate true pressure.

Direct visualization of the anterior chamber angle with a mirrored or prismatic lens to classify open versus narrow angles and identify peripheral anterior synechiae.

Automated static perimetry that measures retinal sensitivity at fixed test locations, summarized by reliability indices, mean deviation, and pattern deviation plots.

Measures of fixation losses, false positives, and false negatives that indicate whether a visual field result can be trusted for clinical decisions.

A visual field plot that adjusts for overall depression of sensitivity, isolating localized defects such as glaucomatous scotomas from generalized loss.

Measurement of corneal curvature and astigmatism, providing base curve guidance for rigid lens selection and detecting irregular or distorted corneal shape.

The distribution of tears under a rigid contact lens observed with cobalt blue light and fluorescein, showing bearing, clearance, and edge lift for fit adjustment.

The height of a lens from its edge plane to its apex, which together with corneal sagittal height determines how a rigid lens will fit.

Application of fluorescein dye viewed under blue light to reveal corneal epithelial disruption, tear film quality, and lens-related insult.

Measurement of the optical power of spectacle lenses using a focimeter, verifying sphere, cylinder, axis, and prism against the prescription.

The separation between the back surface of a spectacle lens and the cornea, which affects the effective power of higher prescriptions.

Determination of prism power and base direction in a lens, using target displacement or lensometer markings to confirm prescribed prism.

Application of a surface agent such as proparacaine to numb the cornea and conjunctiva for tonometry, foreign body removal, or other brief procedures.

A drug that dilates the pupil, such as tropicamide or phenylephrine, used for fundus viewing and cycloplegic refraction with attention to angle-closure risk.

Pressure applied over the tear duct after instilling drops to reduce systemic absorption and increase ocular retention of the medication.

Routine washing or sanitizing of hands before and after patient contact and equipment use, the primary measure for preventing cross-contamination in the clinic.

Explaining the purpose, risks, benefits, and alternatives of a procedure in understandable terms and confirming the patient agrees before proceeding.

A communication method in which the patient restates instructions in their own words so the clinician can verify understanding and correct gaps.