Instruments Used to Examine the Eye

Although often taken for granted, the eyes are most people's central outlet to the world. If you ever need a reminder of their significance, then close your eyes and attempt to navigate your way through a room. Taking care of this organ is critical and when visiting an optometrist, there are several instruments used to examine the eyes. These instruments are classified into two types: one for diagnostic purposes, and the other for determining the current health and status of the eyes.

Ophthalmoscope

• The ophthalmoscope is an instrument used to visualize the back view of the eye. It is classified into two types, including monocular direct and binocular indirect. Monocular direct is a small hand-help ophthalmoscope which visualizes the back portion of the eye, optic nerve, blood vessels and the macula. Although limited in magnification, it can still detect most changes in vision. The instrument is used by setting it within a few millimeters of the pupil, where it then allows viewing of the back portion of the eye. Binocular indirect ophthalmoscopes are worn by optometrists on the head. They use a separate light source and optical system and are often used with a condensing lens. Mydriatic drops are usually used to dilate the pupils of the eye, allowing for a better visualization of the back portion of the eye. More thorough than the monocular direct version, the binocular indirect detects lesions in the eye as well.

Retinoscope

• Retinoscopes examine light refraction by the retina within the internal portions of the eye. This tool helps to measure post-surgery improvements or regressions in patients, especially after major medical procedures, such as corneal refractive surgery.

Slit-Lamp Biomicroscope

• Slit-Lamp Biomicroscopes provide a high magnification, visualizing the entire front portion of the eye, including the cornea and iris. They detect surface tissue damage with the use of a contrast medium, usually in the form of dyes of different colors. They also detect any inflammation of internal structures and are used extensively for fitting contact lenses.

Gonioscopy Test

• The gonioscopy test examines the anterior chamber (or front part) of the eye to determine the presence of glaucoma; this disease causes blindness brought forth by dysfunctional optic nerves. A contact lens with a mirror placed over the eye gives the doctor a view of the space between the iris and cornea where the symptoms of glaucoma usually exist.