BASIC INSTRUMENTS AND EQUIPMENT USED IN OPTOMETRY

Snellen chart

• used in measuring the visual acuity of the patient using letters

phoropter

• used to manually determine “refraction” exactly how a lens must be shaped and curved to correct your vision to a normal state

torch light or penlight

• used for general eye examinations

• to check for pupil’s reaction and eye’s alignment

hand held occluder

• used to take monocular vision

• used in cover / uncover test

• right eyes is always covered first

autorefractometer

• used to provide starting point for the optometrist in subjective refraction tests

• particularly useful when dealing with non communicative people such as young children or those with disabilities

retinoscope

• used in obtaining an objective measurement of the refractive error of a patient’s eyes

Ophthalmoscope

• also called as funduscope

• a test that allows a health professional to see inside the fundus of the eye and other structures

trial box / case

• a box containing lenses, arranged in pairs, a trial spectacle frame, and other devices used in testing vision

trial frame

• an eyeglass frame designed to permit insertion of different lenses used in correcting refractive errors of vision

• has compartments (1, 2, 3, 4)

• lightweight

• adjustable

• it should have a comfortable nose resting

• readily adjustable

1st

high powered lens

2nd

spherical lens

3rd

cylindrical lens

4th

accessory lens and prisms

trial lenses

• during refraction the practitioner utilize a set of known lenses called ____

• used in eye examinations to measure and correct a patient’s vision. It comes in different powers (both plus and minus) and is placed in a trial frame in front of the patient’s eyes.

spherical lens

• all meridians have same power

• there are 32 pairs of ____ in plus and minus power

• used for spherical ametropia

• for hand neutralization

• checking the refracting error

cylindrical lens

• power lies in one meridian

• axis meridian is marked on rim of the lens

• used for correction of astigmatism

• for checking the refractive error

prism

• used to correct and measure strabismus, exercising prism, measure the fusional range

occluder

• used to dissociate fusion

• used to close one eye while the other eye can be tested for visual acuity

pin hole disc

• allows only a pencil of light to pass through the corneas

• helps to determine whether eye has refractive error or pathological errors

maddox rod

• used to detect heterophoria

• to detect cyclophoria

• to measure the squint deviation

• to detect orthophoria

red and green filters

• used for color dissociation

• used to find out suppression of eyes

• to find out diplopia