Author: dreye

visual evoked potential (VEP) is a test that measures how the brain’s visual system responds to visual stimulation. It records tiny electrical signals from the back of the head (the visual cortex) after the eyes see a pattern or flash of light. Clinicians use it to evaluate how well signals travel from the eye through the optic nerve to the brain. It is commonly used in neuro-ophthalmology, optometry, and neurology when vision symptoms are difficult to explain with routine eye exams alone.

electro-oculography (EOG) is a test that records small electrical signals related to eye position and retinal health. It uses skin electrodes placed around the eyes to measure changes in electrical potential as the eyes move. In ophthalmology, it is most known for evaluating retinal pigment epithelium (RPE) function in certain retinal disorders. It is also used in some vestibular (balance) and neurology settings to track eye movements.

multifocal ERG is a retinal function test that records tiny electrical signals generated inside the eye in response to light patterns. It measures how different small areas of the central retina are working, rather than giving one overall average result. It is commonly used in ophthalmology and optometry clinics to evaluate unexplained vision symptoms and to support diagnosis or monitoring of macular and retinal conditions. It is a diagnostic test, not a treatment.

electroretinography (ERG) is a diagnostic test that measures the retina’s electrical responses to light. It helps clinicians assess how well retinal cells are functioning, even when the retina looks normal on exam. It is commonly used in ophthalmology and optometry clinics, hospital eye departments, and specialized retina practices. It can support diagnosis and monitoring of inherited, toxic, and ischemic retinal conditions.

esthesiometry is the measurement of sensation, most often the sensitivity of the cornea (the clear front window of the eye). It helps clinicians understand how well the eye can detect touch or other stimuli on the ocular surface. It is commonly used in ophthalmology and optometry to evaluate corneal nerve function. It can support the assessment of dry eye, nerve-related corneal disease, and recovery after certain eye surgeries.

corneal sensitivity is the cornea’s ability to feel touch, temperature, and irritation. It reflects how well corneal nerves and protective reflexes are functioning. Clinicians use it as a sign of ocular surface health and corneal nerve integrity. It is commonly assessed during evaluations for dry eye, corneal disease, and after eye surgery.

lid eversion means gently turning an eyelid outward to see the inner lid surface. It is most often done to examine the upper eyelid and the tissue behind it. Clinicians use it during routine eye exams and urgent evaluations for irritation or pain. It helps reveal problems that can hide under the lid, such as a foreign body or inflammation.

meibography is an eye imaging test that shows the structure of the meibomian glands inside the eyelids. It is most often used to evaluate dry eye related to meibomian gland dysfunction (MGD). The images help clinicians see gland loss, shortening, or blockage patterns more clearly than with a routine external view. It is commonly performed in optometry and ophthalmology clinics as part of ocular surface and dry eye evaluations.

tear osmolarity is a measurement of how concentrated the tear film is on the surface of the eye. It reflects the balance between water, salts (electrolytes), and other tear components. It is commonly used in eye clinics as part of dry eye disease evaluation and ocular surface assessment. It helps clinicians interpret symptoms and signs that may not always match.

rose bengal is a diagnostic dye used in eye exams to highlight certain problems on the eye’s surface. It is most often used in ophthalmology and optometry clinics during a slit-lamp exam. The dye can make damaged or unprotected areas of the cornea and conjunctiva easier to see. It is commonly discussed in the context of dry eye disease and other ocular surface disorders.

lissamine green is a diagnostic dye used during eye exams to highlight certain ocular surface changes. It helps clinicians see patterns of staining on the conjunctiva and cornea more clearly. It is most commonly used in dry eye and other ocular surface disease evaluations. It is applied as a drop or via a moistened dye strip in the clinic.

fluorescein is a fluorescent dye used to help clinicians see eye surface changes and certain blood vessels more clearly. It is commonly used in eye exams in optometry and ophthalmology clinics. In small amounts on the eye, it highlights scratches, dry spots, and contact lens fit patterns. When given into a vein for imaging, it can help map blood flow in the retina.

ocular surface staining is a clinical test that uses special dyes to highlight the surface of the eye. It helps clinicians see areas where the cornea or conjunctiva may be dry, irritated, or damaged. It is commonly performed during eye exams in optometry and ophthalmology clinics. It is often used when people have symptoms like burning, foreign-body sensation, or fluctuating vision.

Schirmer test is a simple clinical test that measures tear production. It uses a small paper strip placed near the lower eyelid to see how much it wets over time. It is commonly used in eye clinics to evaluate dry eye disease and related conditions. It may be performed by ophthalmologists, optometrists, and trained clinical staff.

tear breakup time (TBUT) is a clinical measure of how long the tear film stays smooth after a blink. It helps clinicians understand tear film stability on the front surface of the eye. It is commonly used when evaluating dry eye disease, contact lens comfort, and fluctuating vision. It can also be part of pre-operative screening before procedures like cataract or refractive surgery.

A keratograph is an eye-imaging device used to assess the shape and surface of the cornea (the clear front window of the eye). It commonly uses reflected light patterns to map corneal curvature and related measurements. Many keratograph systems also evaluate the tear film and eyelid glands that support comfortable vision. It is widely used in optometry and ophthalmology clinics for diagnostics, contact lens fitting, and surgical planning.

biometry means measuring the eye’s physical dimensions with specialized instruments. In eye care, it most often refers to measurements used to plan cataract surgery and choose an intraocular lens (IOL). It can also support refractive surgery planning and help document eye growth or anatomy over time. Results are numerical and are interpreted by clinicians alongside the rest of the eye exam.

IOL biometry is a set of eye measurements used to plan intraocular lens (IOL) power for cataract and lens-based surgery. In plain terms, it helps clinicians estimate what “lens strength” should replace the eye’s natural lens. It is commonly performed before cataract surgery, refractive lens exchange, or some secondary IOL procedures. The goal is to support more predictable vision after surgery.

axial length is the front-to-back length of the eye, measured along its visual axis. It is commonly defined as the distance from the front surface of the cornea to the retina at the back of the eye. Clinicians use axial length as a core eye measurement in cataract surgery planning and in myopia (nearsightedness) evaluation. It is also used in research and clinical monitoring of eye growth and certain eye disease risks.

keratometry readings are measurements of the cornea’s curvature (its front surface shape). They are commonly written as “K” values, often with a flat and a steep meridian. Clinicians use them to estimate corneal focusing power and corneal astigmatism. They are routinely collected in optometry and ophthalmology clinics, especially before contact lens fitting and cataract surgery planning.