A Brief idea about Trial lens box & Accessories

Mainly before uses the trial lens box & accessories
should be know what is the things? how to uses
the accessories? How to works? Why uses the
accessories. It is the most valuable weapon for
Ophthalmologist & optometrist to correction the
refractive error of human eye. Mostly people
known as “trail box”.
we can call as a mobile phoropter with containing
pairs of spherical plus & minus Lens, Cylindrical
plus & minus lens. Trial Spectacles frame, Pin
Hole, Prism Lens, occluder, Plano lens, Red &
green filters, Maddox rod, Prism lens, Stenopaic
Slit etc. 1`

If we see the trial lens box then can see many of
rows & columns of accessories according to the
box, uses for
– Subjective Refraction.
– Objective Refraction.
– Diplopia Charting.

– Diagnosis of squint.
– Assess of Binocular Vision.
 Trial Frame: Mainly It is uses for as a trial
lens insertion show case at the time of doing
refraction (correction the refractive error)
like spectacles trial. It is very light weight,
adjustable for comfortable nose resting,
readymade accurate centering vertically &
horizontally both meridian.
There are various types of trial frames –
1. Full Aperture trial frame.

2. Half Aperture trial frame.

3. Reduce Aperture trial Frame.

There are 3-4 compartment for trial lens

1 st Compartment: High power lens,
2 nd Compartment: Spherical Lens
3 rd Compartment: Cylindrical lens for smooth &
accurate rotation.
4 th Compartment: For accessory lens & prisms.

There are various types set of lenses which utilize
the ophthalmologist & optometrist during
1. Full Aperture Lens
2. Reduced Aperture Lens
3. Plano Lens
4. Spherical Lens

5. Cylindrical Lens

 Full Aperture Lens:

Prism Lens: these types of lens effectively
used to correction of double vision &
binocular difficulties.

Occluder: It is an opaque disc which uses to
determine whether reduced vision is caused
by refractive error.

Red & Green Filter: Red filter for right & green filter for left we
perform to find out fusion, suppression,
squint, diplopia. Even we use to do worth 4 th
Test, FRIEND test.


Dil se Optometrist. Optometrist Intern at ASG Eye Hospitals. Executive member of Optography.

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