The trial case contains spherical and cylindrical lenses of known power ranging from +0.12D to -20.00D for spherical lenses and +0.25D to -6.00D for cylindrical lenses. It also includes prisms up to 10 prism diopters, trial frames, occluders, pinholes, filters, and other accessories used to perform refraction tests and examinations.

1. TRIAL CASE
PRENTER:- PARESHPRENTER:- PARESH
MHATREMHATRE
MODERATOR:- KUNALMODERATOR:- KUNAL
KISHORKISHOR

2. TRIAL CASE
It contains the set of spherical and cylindrical
lenses of known power.
Components present in Trial set are
o Spherical lenses.
o Cylindrical lenses.
o Prism.
o Accessories.

3. Reduce APERTURE LENSES
 Always Plano convex & Plano concave.
 Diameter of the lens is 20mm.
These lenses probably gives the best
approximation.
Use of the lens is neutralize the spectacle
lens with their opposite sign.

4. FULL APERTURE LENSES.
Full aperture:
Always Bi-convex & Bi-concave.
Diameter of the lens is 38mm.

5. Spherical lenses
Present in plus and minus form
Range: +& -0.12D to +& - 20.00D.
Variation:-
 0.25 to 4.00D in increment of 0.25D
 4.00 to 6.00D in increment of 0.50D
 6.00 to 14.00D in increment of 1.00 D
 14.00 to 20.00D in increment of 2.00D

6. Cylindrical lenses
Present in plus & minus form.
Range:- +&-0.25D to +&-6.00D.
Variations:-
 0.25 to 3.50D in increment of 0.25D
 3.50 to 6.00D in increment of 0.50D

7. Principle:-
Displace image towards apex.
PRISM

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Prisms up to 10 prism diopter with addition of
15to20prism diopter.
Range:-0.50,1,2,3,4,5,6,8,10,12 prism dioptre.
It is Plano thickness gradient prism.

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There are mounted with base apex notation.
 Use:
To measure small squint.
To prescribe prism in spectacle.

10. ACCESSORIES
Trial frame
Jackson cross cylinder
Occluder
Pin hole
Stenopic slit
Maddox rod
Red & Green filter

11. Trial frameTrial frame

12. TRIAL FRAMETRIAL FRAME
It is made up of metallic/plastic frame.
Ideal trial frame features are:-
1.Light weight with comfortable nose rest
2.At least 3 compartment one each for
spherical lenses
cylindrical lenses
occluder

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Compartment of cylindrical lens has smooth and
accurate rotation.
Properties of ideal frame:-
Non allergic material.
Nose bridge & temple are adjustable according
to patient face.

14. JACKSON’S CROSS-CYLINDERJACKSON’S CROSS-CYLINDER
The cross cylinder is a combination of two
cylinders.
Their axis at right angles to each other and
mounted in a handale.
The commonly used cross cylinders are of
+&-0.25 or +&-0.50.
It is used for Astigmatic refraction.

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The cross cylinders usually used to refine
cylindrical axis and power of lens.

16. OCCLUDEROCCLUDER
It is black opaque disc & mounted
in metal/plastic rim.
It is used for uniocular testing and
to occlude light reaching the eye.

17. PIN HOLE

18. PIN HOLEPIN HOLE
Pinhole:-
It is black opaque disc with central pinhole
of 1 to 2 mm.
Ideal central pinhole diameter is 1.42mm.
PRINCIPLE:-
It allowed only one ray of light to passed
through along the principle axis of eye.

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USES:-
To see best corrected visual acuity.
Used for macular function test.
To analyzed opacity of cornea is central or
Para central.

20. STENOPIC SLIT

21. STENOPIC SLITSTENOPIC SLIT
It is made of black opaque with slit aperture.
Slit aperture with 15mm length and 1mm width.
It allowed ray of light to passed through only 1
meridian.

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USES:-
To record V/A in 1 meridian.
To find axis of cylinder.
To find principle meridian.

23. MADDOX ROD

24. MADDOX RODMADDOX ROD
It is the series of high power convex cylinder
mounted with their axis parallel to each other.
This available in red and green colours.
Principle:-
It convert spot light into a line.

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USES:-
To diagnose & measured phoria.
To measure conversion.

26. GREEN & RED FILTERS.GREEN & RED FILTERS.

27. GREEN & RED FILTERS.GREEN & RED FILTERS.
Green & Red filters:-
This are red glasses of 640nm & green 535nm
wavelength.
Red filter in front of the RE and Green filter for the
LE.
Principle:-
This dissociate the eye using colour sense.

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In WFDT. (Worth for dot test)
Diplopia charting

29. Thank you