dark room

DARK ROOM APPLIANCES

PROF. DR. D. SUNDARARAJAN. M.S.,D.O.,

Associate Professor in Ophthalmology,

Dr Rajvin Samuel Ponraj

MBBS (MS)

Meenakshi Medical College & Research Institute Kancheepuram

PRISTLEY SMITH RETINOSCOPE

MIRROR RETINOSCOPE

RETINOSCOPE

• Flat handle with mirrors with hole on either side• Plane mirror on one side• Concave mirror on other side• Holes at centre to view through patient’s eye by

examiner• Hole has +2D lens to exclude accomodation

error used to examine at 1mt distance• To determine opacity of media• To determine error of refraction.

TRIAL FRAME

TRIAL FRAME

• Adjustable with IPD by screw

• 3 compartments in front of eye

• Inner : to keep occluder, pin hole, stenopic slit, presbyopic correction

• Middle : to place spherical lens

• Outer : to keep cylinder as in front, it is graduated to know axis.

PLACIDO’S DISC

PLACIDO’S DISC

• Disc with alternate concentric dark and light rings

• Central hole with +2D lens

• Disc attached to a handle

• Examining the reflected image of rings over pt cornea

• To diagnose keratoconus, corneal surface anamolies, ulcers.

MADDOX WING

MADDOX WING

• Instrument that dissociates retinal images of 2 eyes for near

• To diagnose and measure heterophoria or latent squint

MADDOX ROD

MADDOX ROD

• 4-5 cylinders of red glass prisms

• Fused side by side in a round disc frame

• May give the effect given by

• Deeply grooved red glasses(mad groove)

• To detect heterophoria

• As it dissociates two retinal images

• As macular function test

RED AND GREEN GLASSES/FILTERS

RED AND GREEN GLASSES/FILTERS

• Red placed in front of right eye

• Green glass in front of left eye

• Used for diplopia charting

• To test binocular vision in Worth’s four dot test

• For malingering test

CONVEX SPHERICAL LENS

CONVEX SPHERICAL LENS

• Biconvex spherical lens mounted on (metal) frame

• Centrally thick • Images – magnified • Moves in opposite direction in all meridians on

moving lens.• Used in HM, Presbyopia, Aphakia, Compound

HM astigmatism, Mixed astigmatism, Retinoscope, Placido’s disc, Slit lamp, Operating microscope, Simple & Comp microscopes, Telescopes

CONCAVE SPHERICAL LENS

CONCAVE SPHERICAL LENS

• Biconcave spherical lens in (metal) frame

• Centrally thin

• Images minified – moves in same direction as lens moves (in all meridians)

• Used in Myopia, Compound myopic astigmatism, Mixed astigmatism, Hruby’s lens

CONVEX CYLINDRICAL LENS

• Magnified image seen thru it

• Image moves in opposite direction of lens movement

• Image moves 90* perpendicular to axis

• Along axis – no movement

• Axis – plane of zero power

• Used in astigmatism – sim, comp, mixed

CONCAVE CYLINDERS

• Image moves in same direction of lens

movement & opposite to axis

• Along axis – no movement

• Used in astigmatism – sim, comp, mixed

OCCLUDER

OCCLUDER

• Black opaque disc

• To occlude one eye while testing / correcting other eye

PIN HOLE

PIN HOLE

• Black opaque disc with small central 1 mm hole

• Used to find out impaired vision due to RR or ocular path involving media

• Used in macular function test

STENOPIC SLIT

STENOPIC SLIT

• Black opaque disc with vertical / horizontal straight slit at centre

• To differentiate causes of haloes

• Fincham’s test