QUESTION BANK FINAL

1 CHAPTER 1 REFRACTION CHAMBER REFRACTION DEPARTMENT-CBE

2 CHAPTER 1 REFRACTION CHAMBER CONTENTS *Equipments needed in refraction chamber • General equipment • Clinical equipment *Equipment’sand uses: • Occluder • Pinhole • Maddox rod • Stenopic slit • Red And green Flitters • Jackson cross cylinder • Trail frame • Retinoscopy • Phoropter • Auto Refracto meter • Lensometer • PD Ruler scale • RAF ruler • Prism bar • Mydriatics Drugs

Cubical 3 • Dimension and Space management in refraction unit • Arrangements. ABBREVIATION 1.NPC - Near point of convergence 2.OS - Ocular sinister 3.OD - Ocular dexter 4.PHVA - Pinhole visual acuity 5. WD - Working distance 6.ADD - Addition 7.JCC - Jackson cross cylinder 8.DP - Diopter 9.PH - Pinhole 10.ARMR - Autorefractometer 11.SS - Stenopic slit 12. MR - Maddox rod 13.RAF - Royal air force ruler 14.PD - Pupillary distance REFRACTION DEPARTMENT-CBE

4 15.CV - Colour vision 16.PB - Prism bar 17.RC - Refraction chamber 18.HD - Horizontal deviation 19.VD - Vertex distance 20.PM - Plane mirror 21.IPD - Inter pupillary distance 22.MPD - Monocular pupillary distance 23.SR - Streak (or) spot retinoscope 24.NV - Near vision 25.TNO - The netherland of ophthalmology 26.BSV - Binocular single vision 27.FR - Fusion range 28.CM - Ciliary muscle 29.SR - Subjective refraction 30.OR - Objective refraction 31.IA - Irregular astigmatism

5 32.AL - Accessory lens 33.LM - Lensometer 34.SC - Snellen chart 35.ICV - Ishihara colour vision I. FILL IN THE BLANKS : 1.Who is the inventor of refraction………. Ans :Willebrordsnell van royen 2.Who is the inventor of Snellen chart……… Ans :Hermann Snellen 3.A refraction chamber should have …… illumination room Ans : Semi dark room 4.Refraction cubicle length &width........ Ans : 6m, 1 1/2m 5.Refraction evaluation is done to prescribe suitable glasses for correcting the patient’s............. Ans :vision problems 6.We use torch light for .............examination Ans :preliminary REFRACTION DEPARTMENT-CBE

6 7.Adjustable illumination set is mainly used for ......... assessment Ans : Near vision 8.In trial lens set ….. lenses are available 9.Spherical lens are available in range from......... Ans :228 Ans :0.12 D to 20.D 10.Cylindrical lens are available in ranges from......... Ans :0.12 D to 6D 11………… accessory lens are available 12. ……… prisms are available in the trial set Ans :10 Ans :0.5D to 12.0 13.All trial lenses are mounted by...........rim with handgrip Ans :plastic or metal 14.Hand grip are useful for............ Ans :easy handling 15.In cylindrical lens, axis meridian is indicated by special.......... and comes without handles Ans :marks

7 16. Cylindrical lens comes without handle for........... Ans :easy rotation 17.…….. has its apex & base marked on the lens Ans :prism 18.Occluder is a..............material disc Ans :opaque disc 19.Occluder is used to.......... Ans :close or cover the eye 20.Pinhole is used to see ........&if there is any improvement in visual acuity Ans :refractive errors 21. Pinhole actually reduces the retinal blur and allows the central light rays to reach the ............ to enhance vision Ans :macula 22.Pinhole optimum size........... Ans :1.32mm 23.Multiple pinhole are used when patient is not able to view through the visual axis and for patients with........... Ans : low vision REFRACTION DEPARTMENT-CBE

8 24. Maddox rod is constructed by a series of......... rods Ans :red cylindrical rods 25.Maddox rodis used to detect.......... Ans :hetrophoria&heterotropia 26.In maddox rod each rods act as a.......... lens that forms red streak band before the eye Ans :plus cylindrical 27.Stenopic slit consists of a.............. aperture Ans :rectangular 28.Stenopic slit width &length.............. Ans :1mm& 15 mm 29. Stenopic slit is useful for refining the........ Ans :axis of high irregular astigmatism 30.Red & green goggles are mainly used for checking............. Ans :BSV,stereopsis 31.JCChas used to determine.......... Ans :power & refine the axis verified 32.JCC is axis of two cylinders are marked in.......... colors Ans :white & red

9 33.What is the other name of JCC....... Ans :crosscylinder 34.Other name of JCC is .......cylindrical lens Ans :sphero 35.In JCC white mark are......... lens and red mark are.......... lens Ans :minus & plus 36.Cross cylinder are available in..........powers Ans :0.12d,0.25d,0.50d,1d 37.Trial frame is constructed of......... number of cells Ans :4 38.Trial frame is used for keeping the............ lenses Ans :spherical,cylindrical, accessories 39.Trial frame consists of........ knobs Ans :3 40.In trail frame how we place the lens in4 cells ........., ………., ………., ………. Ans :front cell - accessories, second cell -cylinder, third cell – spherical, back cell- high power REFRACTION DEPARTMENT-CBE

10 41.In trail frame two eyes frames are being mounted by an adjustable.......... and........ Ans :bridge & sides 42.Special trial frames are available for ........ and for .......... refraction Ans :childrens& low vision 43.…………..is an objective method Ans :retinoscopy 44.Retinoscope is to determine the.......... status Ans :refractive status 45.Retinoscope isused to estimate refractive error for particularly............ Ans : Un co-operative child,mentally retarded persons 46.Two types of Retinoscope are ........., ……… Ans :spot,streak 47.Other name of phoropteris........... Ans :refractor 48...............is exclusively designed for refraction Ans :phoropter 49.Autorefractometer is used to measure the.......... of the eye Ans :refractive power of the eye

11 50.Autorefractometer is easily operated even by......... persons Ans :non-technical 51.Colour vision test is done by ............ plates Ans :ishihara 52.Ishihara color vision plates is used to screen for......... Ans :colorblindness 53.This chart helps to detect........... deficiencies Ans :red & green 54.Ishihara chart contains..........number of plates Ans :38 55.Lensometer is used to........... Ans :measure the corrective lens power 56.The othername of lensometer is.............. Ans :focimeter 57.IPD ruleris used to measure .... Ans :inter pupillary distance 58.Inter pupillary distance is.......... in milli meter Ans :distance between the center of two pupil REFRACTION DEPARTMENT-CBE

12 59.IPD measurements should be obtained for both........... Ans :near& distance 60.RAF ruler is used to detect the normal range of ............& ……… Ans :convergence&accommodation 61.What are the two types of prism bars...........? Ans :horizontal&vertical 62.Prism bars are used to find …….. range Ans :fusionalrange 63.Horizontal prism bar used to find....... Ans :horizontaldeviation, exoeso 64.Vertical prism bar usedto find........ Ans :vertical deviation, hypo, hyper 65.Mydriatics causes the............ to dilate Ans :pupil 66.Mydriatics stimulates........ muscle Ans :iris dilator muscle

13 67.Mydriatics is used to facilitate the retinoscopy to the patients having opacity of visual axis and for………… Ans :fundoscopy 68.Cycloplegics drugs paralyse..........muscle Ans :iris sphincter muscle 69.Cycloplegic refraction is important in....... Ans :children 70.Cycloplegic frequently interferes with.......... refraction Ans :accurate 71.Expansion of NPA ........... Ans : Near point ofaccommodation 72.Expansion of NPC explanation........... Ans : Near point of convergence 73.The cubicle illumination level required is........... Ans :19 foot candles 74.Patient is seated to........... side Ans : right of the examiner REFRACTION DEPARTMENT-CBE

14 75.Trial frameis invented by........... Ans :Keeler 76.Streak retinoscopy invented by........... Ans :Jack C. Copeland 77.JCC inventedby ........... Ans :William Jackson 78.Subjective refraction inventedby .......... Ans :Polanski 79.Trial frame weightis ......... Ans :52.9 mgs 80.What are the two methods of refraction evaluations .......... &.......... Ans :subjective & objective 81.Plane mirror is used to reflect........... chart at distance Ans :snellen chart

15 II.CHOOSE THE BEST ANSWER : 1. …….. is very essential in eye care practice for doing preliminary vision assessment A] Refraction chamber B] snellen’s chart C] retinoscopy 2.A refraction should be done in ….. Ans :A . Refraction chamber A] Semi dark room B] darkroom C] bright room Ans : A. Semi dark room 3 .….is used to reflect theSnellen chart letters A] Planemirror B] concavemirror C] convex mirror Ans : A. Planemirror 4. …..is used for doing the preliminary examination A] Torch light B] ophthalmoscope C] slit lamp Ans : A. Torch light 5. …..is the primary & most essential device in a refraction chamber A] Trial lens set B] concave&convex lens C] accessory lens Ans : A. Trial lens set 6. Trial lens are mounted either by a ….hand grip for easy handling A] Copper B] iron C] metal(or)plastic Ans : C. metal (or) plastic REFRACTION DEPARTMENT-CBE

16 7. Prism has its apex&base marked on the …..…. A] Lens B] handgrip C] trial set Ans : A . Lens 8. Occluder is an opaque disc used to close one eye during …….. A] Fundusexamination B] refractionexaminationC] squint examination Ans : B. refractionexamination 9. …… is used to determine the decrease in vision due to refractive error or pathological disease of the eye A] Pinhole B] stenopic slit C] Maddox rod Ans : A . Pinhole 10. Maddox rod constists of a series of…… A] Red slit B]red cylindrical rod C]concave&convex cylindrical Ans : B. Red cylindrical rod 11. Maddox rod is used to detect ………, A] Heterophoria B] refractiveerror C] squint Ans : A . Heterophoria

17 12. Stenopic slit consists of a rectangular aperture with a liner slit of ….…. width ….length A] 1mm& 15mm B] 2mm&20mm C] 1mm &3mm Ans : A . 1mmto 15mm 13. ………is used for irregular astigmatism A] Stenopic slit B] sphero cylindrical lens C] placido disc Ans : A . Stenopic slit 14. Red &green goggles are used in …….. A] Binocular single vision B] color vision C] duochrome test Ans : A . Binocular single vision 15. JCC is a combination of ………power A]minus&pluscylinder B]minus&plus sphere C]cylindrical only Ans : A . minus&plus cylinder 16. The axis of two cylinders in JCC are marked in ….............color A] red green B] red white C] white or red Ans : B. red white 17. ……..is available in 0.12, 0.25, 0.50, and 1.0 power A] Concave lens B] convex lens C] cross cylinder Ans : C . cross cylinder REFRACTION DEPARTMENT-CBE

18 18. ……… is holding the trial lenses before the eye during refraction A] Trial frame B] trialset C] retinoscopy Ans : A . Trial frame 19. ……is constructed of three cells on front side &one on back side A] Trialframe B] phoropter C] pediatrics frame Ans : A . Trialframe 20. The front three surfaces of the trial frame are used for …….. A]spherical,cylindrical,accessories B]prism,JCC,Maddox rod C]stenopicslit,cylindrical,prism Ans : A . spherical,cylindrical,accessories 21. The cylindrical lens & the axis are marked …… A] clock wise B] anti clock wise C] counter clock wise Ans : C . counter clock wise 22. Two eye frames are being mounted by an adjustable …… A] Knobe B] bridge&side C] knobe&bridge Ans : B . bridge&side

19 23. The trial frame is adjused depending on the patient’s ….. before starting the refraction test A] Facial asymmetry B] abnormal head posture C] pupillary distance Ans : C . pupillary distance 24.........are available for children & for doing low vision refraction A] Special trial frame B] special trial set C] special streak Ans : A . Special trial frame 25. Retinoscope is one of the most essential tools for determining ………objectively A] Refractiveerror B] myopic&hypermetropic error C] astigmatic error Ans : A. Refractiveerror 26. ….to estimate the refractive error of those who are unable to co –operate particularly children &mentally retarded person A] Torchlight B] retinoscope C] auto refractometer Ans : B . retinoscope 27. How many types are available in retinoscope ?….… A] 1 B] 2 C] 3 Ans : B . 2 REFRACTION DEPARTMENT-CBE

20 28. The streak retinoscope is popular among practitioner because its .……. A] Simple&easy B] cosmeticallygood C] expensive Ans : A . Simple & easy 29. .……is exclusively designed for refraction A] Phoropter B] Lensometer C] auto refracto meter Ans : A. Phoropter 30. …… are comprised ofspherical, cylindrical, prism and all types of auxiliary lenses A] Phoropter B] trial frame C] phoropter&trial frame Ans : C . phoropter&trial frame 31. ..…..represents the most advanced technology of measuring therefractive power of the eye A] ARMR B] phoropter C] JCC Ans : A . ARMR 32. ARMR can be easily operated even by ……. Person A] Technical B] non-technical C] technical &non-technical Ans : C . technical&non-technical 33. ARMR provides a quick reliable guideline for the …… refraction A] Objective B] subjective C] subjective&objective Ans : A . Objective

21 34. ………..are used for screening of color blindness A] Ishiharacolor vision plates B]duochrometest C]binocular vision test Ans : A . Ishiharacolor vision plates 35.Ishihara chart used to detect ………color deficiency A] Red&green B] red&blue C] allcolor Ans : A . Red&green 36. Ishihara chart contains how many plates ….………. A] 38 B] 15 C] 23 Ans : A . 38 37. How many path way &numbers are there in ishihara chart …….. A] 13&25 B] 25&13 C] 23&15 Ans : A . 13&25 38. …...is used for verify lens power A] Lensometer B] autorefractometer C] phoropter Ans : A . Lensometer REFRACTION DEPARTMENT-CBE

22 39. Lensometer used to detect the ………power A] sph/cyl/prism B] spherical only C] spherical&cylindrical Ans : A . sph/cyl/prism 40.……..is provide the dioptric power of convergence &accommodation A] Prism bar B] RAF ruler C] PD ruler Ans : A . Prism bar III . MATCH THE FOLLOWING Refraction - Occuluder 9 1. Evaluation - Fusion Range 6 2. Plane Mirror - Prism 29 3. Trial Frame - Heterophoria 7 4. Near Vision Chart Irregular Astigmatism 12 5. Snellen’s Chart3m - Minus Lens 11 6. Prism Bar - Red&Green Glass 17 7. Maddox Rod - Maddox Rod 16 8. Topical Drugs - Cover One Eye 13 9. Accessory Lens - Mentally Retarded 22 10. Convex - Vision Problem 1 11. Concave - Snellen’s Chart 2 12. Stenopic Slit -

23 13. Occuluder - 33cm-40cm 4 Pupil Dilate 23 14. Pinhole - Retinoscopy 31 Color Blindness 24 15. Base&Apex - Glass Prescription 34 Distance Vision 33 16. Cylindrical Rod - Cycloplegic Drops 35 Refraction 21 17. Bsv - Power&Axis 18 Near and Distance 27 18. Jcc - Plus Lens 10 Simple&Easy 23 19. White Mark - Focimeter 26 Minus 19 20. Red Mark - Plus 20 Prism 15 21. Phoropter - 60 W 32 Convergence 28 22. Retinoscopy - Enhance Vision 14 Mydriatics 8 23. Streak Retinoscopy - Essential Device 3 6m 5 24. Mydriatics - Paralysis Of Accommodation 30 25. Ishihara Chart - 26. Lensometer - 27. Pd Ruler - 28. Raf Ruler - 29. Horozontal Deviation - 30. Cycloplegic Drops - 31. Objective Refraction - 32. 19foot Candle - 33. Snellen’s Drum - 34. Refractive Error - 35. Accurate Refraction - REFRACTION DEPARTMENT-CBE

24 IV. TRUE OR FALSE : 1.Vision is very essential in eye care practice for doing preliminary vision assessment Ans : False 2.Refraction cubical arrangement 3cm -6cm Ans : False 3.Streak retinoscope is a general equipment Ans : False 4.PD ruler used for pupillary measurement Ans : True 5.Colour vision chart is used to detect the colour blindness Ans : True 6.Lensometer is used to detect the refractive error Ans : False 7.Maddox rod consists of the cylindrical rod- Ans : True 8.Prism has its apex and base marked on the lens Ans : True

9.Occluder is an opaque disc 25 10.Multiple pinhole is used for low vision patient only 11.Maddox rod determines the heterophoria Ans : True 12.Stenopic slit is useful for refining the axis of refractive error Ans : False Ans : True Ans : False 13.Red green goggles are used in checking the BSV Ans : True 14. WFDT is used for color vision Ans : False 15.JCC is a spherocylinder Ans : True 16.The trial frame is a metallic frame for holding the trial lens 17.Retinoscope is the only device to estimate the refractive error Ans : True Ans : True REFRACTION DEPARTMENT-CBE

26 18.Refractor is exclusively designed for refraction Ans : True 19.ARMR is a guideline for the objective refraction Ans : True 20.Lensometer is called as autorefractometer- Ans : False 21.PD ruler measurement should be obtained for distance ,for each patient Ans : False V.UNSCRAMBLE WORD 1.REFRACTION - FOTNRCEAOI 2.VISION ASSESSMENT - SISETSVIMSOENAS 3.REFRACTION CHAMBER- IHRRRMEOFTCNBACAE 4.OBJECTIVE - VBEOTJCIE 5.PLANE MIRROR - NOMWPARILE 6.ILLUMINATION - INTLLUONIMAI 7.TORCH LIGHT - TLCGIOHTRH 8.TRIAL FRAME - MLTERIAFEA

27 9.NEAR VISION - OIVIENASNR 10.SNELLEN’S VISION - SENSIOLNLNVIES 11.PROJECTOR - JPTEOCRRO 12.AUTOREFRACTOMETER- AORTOERAFMTUEE 13.OCCLUDER - COCELURDU 14.PINHOLE DISC - DCNPIHLSEOI 15.MADDOX ROD - RDDXDAMOO 16.STENOPIC SLIT - STLECNIOPTSI 17.PRISM LENS - PMESRNILNS 18.COLOUR VISION - OOOICNLRISV 19.LENSOMETER - SERLNTEEOM 20.MYDRIATICS - ICYDMRATI 21.MINUS LENS - NISLMEUSN 22.PLUS LENS - SPNEULLS 23.CYLINDRICAL LENS- LYNSELCICNRDLAC 24.SPHERICAL LENS - PEHSARCILNELS 25.ACCESSOR LENS - CNESLCSCARYOE REFRACTION DEPARTMENT-CBE

28 26.MERIDIAN - AREIDMIN 27.OPTIMUM - MUOPTMI 28.CYLINDRICAL ROD - CNIYLNRIDLACFOR 29.HETEROTROPIA - EPOETTOHRRIA 30.HETEROPHORIA - TPOEHROIHRA 31.IRREGULAR ASTIGMATISM - AMSITGRRIEMGAUTLAIR 32.STEREOPSIS - TOESEPSIRSE VI.CORRECT THE SENTENCE 1.Pinhole blurs the image Ans : sharpens 2.Jackson cross cylinder is a combination of cylindrical lens Ans:spherocylinder lens 3.Pinhole is used to occlude one eye Ans :occluder 4.Duochrome test is detect the colour blindness Ans :colour vision

29 5.Retinoscope used to measure corrective lens power Ans :lensometer 6.Retinoscope is used the only device to estimate the fundus Ans :refractive error 7.Convex mirror to reflect the snellens chart Ans : plane mirror 8.Torch light is necessory for fundus examination Ans : preliminary 9.Trial set contains the plus and minus lens only Ans :pair of plus and minus sphere and cylinder lens with prism and accessory lens 10.Maddox rod has its apex and base marked on the lens Ans : prism 11.Red and green is used for colour vision test Ans : binocular single vision and stereopsis 12.Pinhole allows the peripheral rays to reach the macula Ans : central 13.Maddox rod measure the amount of fusion REFRACTION DEPARTMENT-CBE

30 Ans : hetero phoria 14.Maddox rod consists of a rectangular aperture Ans :stenopic slit 15.Cycloplegic drops is used to constrict the pupil Ans : dilate 16.Autorefractometer comprised of spherical lens, cylindrical lens prism and all type of auxillary lens Ans :phoropter 17.IPD measurement should be obtaindeddistance only Ans : near anddistance VII. GIVE THE USES FOR THE FOLLOWING INSTRUMENT/TESTS 1. Occluder - Opaque disc used to cover the eye Axis And power verification in cylindrical 2. JCC 3. Cycloplegic - power 4. Prism bars - Controls the action of ciliary muscles 5. Near visual acuity - Set Of prisms with varying power - Sharpness of vision at near point 6. Lensometer - It Is used measure the back or front vertex

7. Occluder 31 8. Cycloplegics 9. Reason for vision detect power of a spectacle lens - Opaque disc used to cover the eye - Controls the action of ciliary muscles - Loss of cone cell VII. GIVE THE REASON 1.Why do we set refraction cubicle dark Ans: To measure the correct refraction power. 2.Why is pinhole used in the refraction Ans: To check the improvement of vision and identify the refractive the refractive error and pothological disease 3. Why do we use cycloplegic drops for hypermetorpiapatient ? Ans: To relax accommodation 4.Pinhole enhance vision. How? Ans: Allows only the central rays to reach the retina 5.What measurement is used to measure prism power? Ans: Extent of deviation produced as light passes through it 6.What is the use of pseudo ischromaticcolour plates? Ans: To evaluate colour vision REFRACTION DEPARTMENT-CBE

32 7.What type of drops is used to paralyse the ciliary muscles and dilate the pupil? Ans:Cycloplegic drops 8.A pinhole size of 1.32mm is most effective. Why? Ans: It produces the smallest blur circle 9.Whywa are used pinhole for refraction? Ans: There is a limit to pinhole size for clear vision 10.Inter pupillary distance should be measured for both the near and distance why? Ans: It is measured to align the center of your eye glass lenses with the center of your eyes properly 11.Why we are using trial frame for refraction? Ans: Trial frame is used for holding the trial lenses during refraction 12.Why we are using stenopicslit ? Ans: It is used to determine the vertex distance and refining the axis of high irregular astigmatism 13.What is used to find the fusional range? Ans : Prism bar is used to find the fusional range 14.What is the other name of retinoscopy? Ans:Skiascopy

33 15.What are the charts used for near vision? Ans:Jaggers chart is the one type of near vision IX. DRAW THE DIAGRAM 1.Refraction cubicle set up 2.Draw the JCC 3.Draw the occlude and pinhole 4.Draw the maddox rod and stenopic slit 5.Draw the trail frame X . TRANSLATE ENGLISH TO TAMIL : 1. Refractometer - ஒளிவிலகல்அளவடீ ்டுகருவி உருளளவில்ளல 2. Cylindrical Lens - முப்பட்ளைகஆற்றல் காட்சிகூர்ளை 3. Prism Power - முன்னுரிளைதேைல் 4. Visual Acuity - வண்ணபார்ளவ Preferential - பிறவிைதயாபியா ைாற்றுபார்ளவ 5. Looking அகநிளலஒளிவிலகல் 6. Colour Vision - 7. Congenital Myopia - 8. Alternate Vision - Subjective - 9. Refraction REFRACTION DEPARTMENT-CBE

34 - இரட்ைபார்ளவ 10. Diplopia XI . TWO MARK QUESTIONS : 1.Write about generalequipment for refraction chamber? Page no : 2( Manual book ) 2.Write about the clinical equipment for refraction chamber? Page no : 2( Manual book ) 3.Define occluder? Page no :3 ( Manual book ) 4.Define pinhole? Page no :3 ( Manual book ) 5.What is Maddox rod? Page no :3 ( Manual book ) 6.What is stenopic slit? Page no : 3 ( Manual book ) 7.Whatis a use of red &green glass? Page no : 3 ( Manual book ) 8.What is JCC? Page no :3 ( Manual book )

9.Define retinoscope . 35 10.What is phoropter? 11.Write about the ARMR? Page no : 4 ( Manual book ) 12.What is the use of Lensometer? Page no : 2( Manual book ) 13.Define colour vision? Page no : 2( Manual book ) 14.Write about PD ruler scale? Page no : 2( Manual book ) 15.Define RAF ruler? Page no : 2( Manual book ) 16.What is prism bar? Page no : 2( Manual book ) Page no : 2( Manual book ) XII . FIVE MARK QUESTIONS : Page no : 2( Manual book ) 1.Write about the trial lens box? Page no : 2( Manual book ) REFRACTION DEPARTMENT-CBE

36 2.Write about the trial frame? Page no : 3,4 ( Manual book ) 3.Write about the clinical equipment in refraction chamber? Page no : 2( Manual book ) 4.Drawing- refraction chamber . Page no : 6 ( Manual book ) 5.Write about the tropical drug and action? Page no : 5 ( Manual book ) XIII. TEN MARKS QUESTIONS: 1. Explain about the equipment’s needed in refraction chamber? Page no : 2 , 3 , 4 , 5 ( Manual book ) XIV .JUMBING WORDS : 1. P—S—CE - Presence 2. –LA-E-T - Filament 3. –BLE - Table Forms 4. F---S - Circulation 5. C—C-LA—ON -

37 WORKSHEET 1. Write about the various types of pinholes ? 2. How do we measure the amount of hetrotropia ? 3. Explain about the enlarged pinhole ? 4. How do we use the JCC ? 5. Write about phoropter ? 6. Write about the types of prism bar and uses ? 7. Write about the colour vision chart ? 8. Write about the cubicle dimension ? REFRACTION DEPARTMENT-CBE

38 9. Write about the difference between PD ruler and RAF ruler ? 10.What are the topical drugs that are used for cycloplegic ? 11.Explain about the advantage of the retino scope ?

39 CHAPTER 2 OPTICS REFRACTION DEPARTMENT-CBE

40 CHAPTER 2 OPTICS CONTENTS Properties of light • Light travels in a straight line • Reflection • Refraction • Scattering • Interference • Diffraction • Polarisation Laws of reflection • First Law • Second Law Laws Of refraction • First Law • Second Law Refractive index Prism • Prism diopter

41 Types of lens • Biconvex • Plano convex • Meniscus lens( concave & convex) • Biconcave • Plano concave Important terms relating to lens • Optical Centre • Principle axis • Focal point • Focal length • Power of a lens Type of lenses • Concave lens • Convex lens Vergence ABBREVIATION 1. D - Diopter 2. - Prism REFRACTION DEPARTMENT-CBE

42 - Far point - light amplification stimulated emission of radiation 3. F 4. LASER I. CHOOSE THE BEST ANSWER : 1. Light is a form of energy interaction with ……..Gives the sensation of light. A] Retina B] cornea C] lens Ans : A . Retina 2. Light is the visible portion of the ………. Radiation spectrum A] Magnetic B] gravity C] electromagnetic Ans : C . electromagnetic 3. Electromagnetic radiation spectrum lies between Of ………. A] Ultra-green&blue B]intrared&yellow C]ultra violet&infra-red Ans : C .ultra violet&infra-red 4. Wave length of violet spectrum ……… A] 400nm B] 330nm C] 500nm 6. White light consists of ………. Colors Ans : A . 400nm Ans : C . 7 A] 6 B] 5 C] 7

43 7. In …….. Theory light consist of a stream of tiny particles called corpuscleswhich are emitted by a source of light s A] Huygens wave theory B] Einstein quantum theory C] newton theory Ans : C . newton theory 8. …….. Particular travel without being affected by earth pulls of produce sensation of light when they enter the eye A] Atom B] proton C] corpuscles Ans : C . corpuscles 9. Newton’s corpuscular theory explained the phenomenon of propagation of light through …….. A] light, refraction B] air, reflection of light C] vacuum, reflection Ans : C . vaccum, reflection 10. Newton’s corpuscular theory could not explain a number of phenomenon’s such as …….. A] diffraction, refraction, reflection B] interference, diffraction, polarization C] a,b Ans : B . interference, diffraction, polarizations 11. Newton’s corpuscular theory failed to explain why light travels faster in …… [A].Than material medium A] Vacuum B] water C] lens Ans : A . Vacuum 12. Huygens proposed that light moves in the form of …… from the luminous source REFRACTION DEPARTMENT-CBE

44 A] Radiation B] wave C] spectrum Ans : B . wave 13. Light wave consists of …….…….. A] crests& troughs B] crests & wave C] particles & crests 14. Trough of crest ………. In shape Ans : A . crests& troughs A] Square B] circular C] rectangular Ans : B. circular 15.The focus of point in same place at a particular time is called a..… A] Wave length B] wave C] wave front Ans : C . wave front 16. The shape of the wave front depends upon the …….. A] Nature of source B] nature of light C] light waves Ans : A . Nature of source 17. Waves from a point source in air of the wave front are ……… A] Cylindrical B] spherocylinder C] spherical Ans : C. spherical 18. If the light source is along slit of the wave front are…….. A] Cylindrical B] sphero-cylinder C] spherical

45 Ans : A . Cylindrical 19. An important characteristics of wave motion is that transmits ……. not A] energy, matter B] matter, energy C] particle, energy Ans : A . energy, matter 20. Huygens theory successfully explains phenomenon of ……… and ………. A] diffraction, reflection B] interference, refraction C] interference, diffraction Ans : C . interference, diffraction 21. Maxwell proposed light consist of ……… of fields travelling free through vacuum A] magnetic, wave B] electric, magnetic C] spectrum, magnetic Ans : B. electric, magnetic 22. Maxwell proposed light is not a ………. Wave A] Electromagnetic B] magnetic C] mechanical Ans : C . mechanical 23. Maxwell theory explains the phenomenon related to light satisfactorically but her partial successin explaining ………. And Fails completely to explain the …….…… effect of light A] scattering, photo chromatic B] scattering, photo chromatic C] a, b Ans : A . scattering, photo chromatic REFRACTION DEPARTMENT-CBE

46 24. Einstein proposed that light of a given frequency consist of …. With same energy A] Neutron B] electron C] photons Ans : C . photons 25. Photons can be considered the units in which the …………. Radiation is measured A] Electromagnetic B] magnetic C] mechanical Ans : A . Electromagnetic 28. Ultra violet rays produce…… A] Injury B] burns C] swelling Ans : B . burns 29. X rays produce severe damage to …… A] Skin B] muscle C] tissue Ans : C . tissue 30. ………. And ……….. Also has dual nature A] matter, light B] light, particle C] wave matter Ans : A . matter, light 31. Light behaves as ..….. As it passes through air, vacuum or parent ocular tissue

47 A] Wave B] frequency C] magnifier Ans : B . frequency 32. A light photon is absorbed in sensitive layer of the …….… A] Cornea B] lens C] retina Ans : C . retina 33. A light photon is absorbed in one of the sensitive cell of the retina. The chemical change induces a …. Signal to the brain A] Magnetic B] gravity C] electrical Ans : C . electrical 34. Speed of light in free space is ……… A] 3 x 10 m/s B] 4 x 10 m/s C] 3 x 108 m/s Ans : C . 3 x 108 m/s 35. Light is transverse in nature of can be ……… A] Polo raised B] transmission C] spectrum Ans : A . Polo raised 36. Light is not reflected by ….….. Fields A] Magnetic B] gravity C] electromagnetic Ans : C . electromagnetic 37. When light pass one meridian to another velocity , wave length change ,……. May decrease or remain constant A] Particle B] scattering C] amplitude REFRACTION DEPARTMENT-CBE

48 Ans : C . amplitude 38. Colour of light is determined by its …… A] Frequency B] velocity C] amplitude Ans : A . Frequency 39. The speed of light in a medium is lesser than in………. A] Water B] prism C] vacuum Ans : C . vacuum 40. Light of a single wavelength is called [B] A] Photo chromatic B] monochromatic C] polo raised Ans : B . monochromatic 41. White light is ………… A] Heterochromatic B] photo chromatic C] polo raised Ans : A . Heterochromatic 42. The media of the eye are uniformly permeable to the visible rays between …[C]….. Nm A] 400-450nm B] 400-800nm C] 600-390nm Ans : C . 600-390nm 43. Cornea absorbs rays shorter than …….nm

49 A] 600nm B] 295nm C] 335nm Ans : B . 295nm 44. The light ray between ……nm only can reach the crystalline lens A] 600-295nm B] 335-350nm C] 400-335nm Ans : A . 600-295nm 45. The normal human eye insensitive to wavelength between …..….nm A] 400-350nm B] 400-800nm C] 600-390nm Ans : A . 400-350nm 46. In aphakia eyes are sensitive to these wavelengths which give rise to the sensation of ……. Colour A] Red, green B] infract or blue C] blue or violet Ans : C . blue or violet 47. Inaphakia eye the ray between ….nm can also pass on the retina A] 350-400nm B] 400-800nm C] 600-390nm Ans : A . 350-400nm 49. The change of brightness necessary to be noticed is ……... to the original brightness A] Infinity B] proportional C] a,b Ans : B . proportional 50. A difference is noticed in a bright light source is ………. than in a dim one A] Equal B] smaller C] larger REFRACTION DEPARTMENT-CBE

50 Ans : C . larger 51. Wave length is a light wave is defined as the distance between two …. Parts of the wave motion A] Symmetrical B] asymmetrical C] equal Ans : A . Symmetrical 52. A light wave is the ……. Displacement of an imaginary particle on the wave from the base line A] Maximum B] minimum C] equal Ans : A . Maximum 53. One complete oscillation of light waves is called a ……. A] Phase B] cycle C] amplitude Ans : B . cycle 54. Any partition of the cycle is called as ….. A] Velocity B] amplitude C] phase 55. Light waves that are out of phase are called … …… Ans : C . phase Ans : B . incoherent A] Coherent B] incoherent C] cycle 56. The light composed of waves exactly in phase is termed ……. A] Coherent B] incoherent C] amplitude