MOC PQA Optometrist key terms

The sharpness of central vision measured by identifying letters or symbols on a standardized chart at a set distance, recorded as a fraction comparing the patient's performance to normal.

The process of determining the lens power needed to focus light correctly on the retina, either objectively with instruments or subjectively by asking the patient to compare lens choices.

A refraction performed after paralysing the ciliary muscle with drops, removing accommodation so the true refractive error is revealed, especially useful in children and suspected hyperopia.

The eye's ability to increase optical power by contracting the ciliary muscle and thickening the crystalline lens, allowing clear focus on near objects.

The age-related loss of near focusing ability caused by stiffening of the crystalline lens, typically becoming noticeable in the early to mid-forties and managed with reading additions.

The positive lens power added to a distance correction to restore comfortable near vision, chosen from the patient's amplitude of accommodation and preferred working distance.

The maximum change in optical power the eye can produce, measured as the difference between the far point and near point of accommodation, and used to plan reading additions.

The fluid pressure inside the eye, measured in millimetres of mercury by tonometry, with elevated values being a major modifiable risk factor for glaucomatous damage.

Any technique for estimating intraocular pressure, such as applanation, rebound, or non-contact air-puff methods, each with specific calibration and technique requirements.

The measured thickness of the cornea, which influences applanation tonometry readings and is an independent risk factor in glaucoma assessment.

Examination of the anterior chamber angle using a mirrored contact lens to distinguish open from narrow or closed angles and to look for abnormal vessels or pigment.

Perimetry that maps the patient's sensitivity across the field of vision, used to detect and monitor defects from glaucoma, neurological disease, or retinal damage.

Enlargement of the central depression of the optic nerve head relative to the disc rim, a structural sign of retinal ganglion cell loss in glaucoma.

A group of progressive optic neuropathies characterised by retinal ganglion cell loss and characteristic disc and field changes, with raised intraocular pressure as the main treatable risk factor.

A form of glaucoma in which the iris obstructs the drainage angle, causing acute or chronic pressure rise, and which requires urgent recognition and referral when acute.

Microvascular damage to the retina from chronic hyperglycaemia, ranging from non-proliferative signs such as microaneurysms and haemorrhages to proliferative disease with neovascularisation.

Fluid accumulation within the macula causing retinal thickening and central vision loss, commonly complicating diabetic retinopathy, uveitis, or cataract surgery.

Degeneration of the central retina in older adults, classified as dry with drusen and atrophy or wet with choroidal neovascularisation, causing central vision loss.

A grid chart used for home and in-office monitoring of central visual field distortion and scotomas, helping patients detect progression of macular disease early.

Distortion of vision in which straight lines appear bent or wavy, typically caused by retinal elevation or traction in the macula.

Non-invasive cross-sectional imaging of the retina and optic nerve using low-coherence light, used to quantify macular thickness, fluid, and ganglion cell loss.

Direct or indirect visualisation of the retina, optic disc, and vessels, including dilated biomicroscopy, to detect and document ocular and systemic disease.

Dilation of the pupil, produced pharmacologically by a sympathomimetic or by blocking the iris sphincter, and required for thorough fundus examination.

A drug that dilates the pupil, such as tropicamide or phenylephrine, chosen for adequate dilation with the shortest useful duration of action.

A surface-acting agent such as proxymetacaine or oxybuprocaine that numbs the cornea and conjunctiva for tonometry or foreign body removal, with no lasting therapeutic effect.

Application of fluorescein dye to the ocular surface, viewed with cobalt blue light, to reveal corneal epithelial defects, abrasions, or tear film abnormalities.

A defect in the corneal epithelium caused by trauma or foreign bodies that stains with fluorescein and risks infection or recurrent erosion if not managed correctly.

Magnified examination of the anterior and posterior segments using a focused slit of light, enabling depth assessment of ocular tissues with or without additional lenses.

A binocular vision test in which each eye is alternately covered to reveal manifest and latent strabismus by observing fixation movement of the uncovered eye.

Misalignment of the eyes in which the visual axes do not point at the same object, classified by direction, frequency, and whether it is constant or intermittent.

Reduced best-corrected vision in one or both eyes caused by abnormal visual experience during development, such as strabismus, anisometropia, or deprivation, and treatable if detected early.

A clinically significant difference in refractive error between the two eyes, which can cause aniseikonia and amblyopia in children if uncorrected.

The ability to detect differences in luminance between an object and its background, measured with gratings or charts and often impaired before acuity in disease.

Visual impairment that cannot be corrected by ordinary spectacles, contact lenses, or surgery and interferes with daily activities, managed with magnification and rehabilitation.

Consistently raised intraocular pressure without detectable glaucomatous optic nerve or visual field damage, monitored over time for conversion to glaucoma.

A patient's voluntary agreement to an examination or treatment after receiving and understanding information about purpose, risks, alternatives, and consequences of refusal.

The structured transfer of a patient's care to another practitioner, including a clear reason, relevant findings, urgency, and expectations for communication back to the referring optometrist.

The contemporaneous, legible, and secure documentation of findings, advice, and decisions in a patient's clinical record, supporting continuity of care and medico-legal defence.

A quality improvement cycle that compares recorded practice against an agreed standard, identifies shortfalls, implements change, and re-measures to confirm improvement.

The framework through which a practice assures and improves quality and safety, covering standards, risk management, incident reporting, education, and accountability.

Any event or near miss that could have caused or did cause avoidable harm to a patient, which should be reported, investigated, and used to prevent recurrence.

Activities that help patients improve or protect their health, such as smoking cessation advice, diabetes control, and eye protection counselling, delivered opportunistically in practice.

Systematic testing of an asymptomatic population to detect disease at an earlier, more treatable stage, judged against criteria for validity, acceptability, and effective follow-up.

The organised effort to protect and improve the health of populations through prevention, surveillance, policy, and equitable access to eye care services.