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NCLE Review
NCLE Test review
| Question | Answer |
|---|---|
| This Test Measures Quality of the Tears | B.U.T TEST (Break Up Time) |
| What is the O2 Permeability | DK Value of a lens |
| What are the Disadvantages of Soft Lenses | Doesn't correct Irregular Astigmatism Favors Deposit formation |
| For succesful contact lens wear, EOP should be at least | 7% |
| This test Measures the Quantity of the Tears | The Schirmer Test Good result is 15mm in 5 minutes Dry eye is 5 to 10mm in 5 minutes |
| Neovascularization is mainly due to what | Hypoxia, Corneal Edema, Tight Contact lens Fit |
| the Radii and Power of an average Cornea | 7.85 mm or +43.00D |
| what are the Layers of the Cornea | Epithelium, Bowmans' Layer, Stroma, Descemet's Membrane, Endothelium |
| The Main Disadvantage of Soft contact lenses | Protein Deposits |
| What is it when we use Contact Lenses to Correct high Myopia | Orthokeratology (Ortho-K) |
| A Contact Lens with diameter that is larger than the Cornea is a Hydrophobic or Hydrophilic | Hydrophilic |
| Which of the following Curves, indicates the flattest Base Curve 7.50mm, 37.50 D, 8.60mm, 49.00 D | 37.50 D |
| A CTL was ordered with a BC of 7.85mm but was received from the lab with a BC of 7.80mm. The BC of the actual lens is | 0.25D steeper than the ordered CTL |
| a CTL with BC of 7.42mm is fitting too loose, a tighter fit may be achieved by changing the base curve to: 7.46mm , 7.85mm , 8.04mm , None of these | None of these.... S.S.S Rule |
| A CTL has a BC of 7.50mm, what would the PPC most likely be? 7.45mm , 42.50D , 7.35mm , 30.00D | 30.00D = 11.25mm / S.S.S Rule |
| What does the Term Haptic Lens refer to? | A Scleral CTL Size |
| The Secondary Curve of a RGP CTL is Generally Flatter or Steeper than the CPC and by How much? | Flatter by 2 to 4 Diopters |
| When the Power of a curve changes by 0.50D , the radius of the Curvature Changes by approximately how much? | 0.10mm |
| The CPC of a CTL measures 7.5mm Radius, how much is the Power in Diopters? | 45.00D |
| A soft CTL demonstrates excessive movement. This can be fixed with a Lens that has a ______________ Diameter? | Larger Diameter. (Larger Diameter = Steeper Fit = Tighter Fit) |
| HEMA is an Abbreviation commonly used to describe what Lens? | the Chemical name for Soft CTL |
| what is the main reason to utilize a Ballasted CTL? | to have less Rotation of the CTL (usually used in bifocal CTL's) |
| The Central portion of the Back surface of the CTL is called? | CPC (Central Posterior Curve) or the Base Curve (BC) or the Optic Zone |
| The Distance between a Flat Surface and the Back surface of the Central Portion of a Lens is called the................ | Sagital Depth ( Vault, height) |
| A loose fitting CTL can be made to fit tighter by ___________ the Radius of the CPC. | Shortening the radius of the CPC. S.S.S Rule |
| what is an example of a Hydrophilic Lens Material? | HEMA |
| A Contact Lens in which the anterior surface contains 2 different radii of Curvature and the Posterior surface is Spherical curve is called a ................... | Front surface Toric |
| The Central Portion of a CTL which contains the refractive power of the CTL is the ...... | Optic Zone (OZ) |
| A CTL which contains 2 curves, One BC and One Secondary Curve. | Bicurve CTL |
| The Smoothing of the junction zones by removing the sharp line between the zones is...... | Blending of the curves |
| The measurement from one edge of the lens to the opposite edge is........ | Chord Diameter |
| A lens which has been cut off to form a horizontal base which improves stabilazations....... | Truncated Lens |
| the effective power of a lens when measured from the back surface....... | BVP Back vertex power... |
| wetting angle means..... | the angle that the edge of bead of water makes with the surface of the plastic... the smaller the angle, the greater the wetting ability |
| A lens in which the anterior surface has two different radii and the posterior surface is spherical.... | Front Surface Toric Lenses |
| A Lens in which both the posterior surface has two different radii and the anterior surface has two different radii is........ | Bi-Toric |
| A lens design generallly used in higher plus powers which consists of a central optic zone and a surrounding non-optic peripheral or carreir portion is.... | Lenticular Bowl |
| a method of manufacturing soft contact lenses whereby a liquid material is revolved in a mold at a controlled speed and temperature which produces the desired curvature, design, and power....... | Spin-Cast lenses |
| When we add 50% of the Cylinder to the sphere and determine a Spherical Prescription it's called...... | Spherical Equivelant |
| The Tear Film Layers from inside out are.... | Mucin, Aqueous, Lipid |
| This Tear Film layer will change the corneal surface from an Hydrophobic surface to a Hydrophilic Surface..... | Mucin Layer |
| The Lipid Layer has a Primary function of..... | Preventing Evaporation of the Tears |
| what age group has the best prognosis for successful Contact Lens Fitting........ | 13-38 |
| When moved 5mm from it's original position the effective power of a 10.00 D lens will change by........... | 0.50D |
| when do we consider vertex distance compensation for Spectacles and for CTL's? | Spectacles 7.00D CTL's 4.00D |
| Spectacle Lens is Prescribed at -10.00D, if the lens fit is at a vertex distance of 10mm, an RGP ctl fit on K will require a power of how much? | -9.00D Minus Lens Coming Closer Gains Power |
| RX -4.00+1.00x90 K: 42.50@180/43.50@90 RGP CTL fit on K has a power of......... | -3.00DS |
| +11.00+1.00x20 VD = 12mm K: 46.25/47.25 What's the power of RGP lens fitted on K | +13.00D +13.25D +13.50D all are correct... NCLE will say +13.00D |
| -3.00-0.50x90 VD = 11 What's the RGP CTL power fit 0.50D steeper than the flattest corneal merridian? | -3.50D VD doesn't matter since rx is less than 4.00D |
| -2.50+0.25x90 VD = 12mm power of CTL if fit 0.75 steeper than K.... | -3.00D |
| The CPC of a trial CTL is 44.00D and contains a power equal to +14.87D. The over refraction is equal to -1.62D. What is the Final CTL Rx if the CPC to be ordred is 43.62D.... | +13.63D (LLP= +0.38D) |
| A -3.50D Lens with a base curve of 44.50D provides excellent visual acuity. if the CPC were changed to 45.00D what power would be needed? | -3.00D (LLP = -0.50D) |
| a Dry Eye condition can be evaluated with a test called........ | Schirmer Test |
| RX -3.25D-1.00x180 K = 44.25@180 / 45.25@90 Vertex Distance 12mm what is the power of RGP CTL fitting 0.50D Flatter than K | -2.75D |
| How do you assess the quality of the peripheral curves of a RGP lens? | using a Shadowgraph |
| Patient is wearing a RGP lens in the right eye, it has a power of +3.00D and a base curve of 43.25. if the Dr Refracts -0.50D sphere over this lens and a new lens is to be ordered with a BC of 43.00, what will the new power need to be? | +2.75D |
| the optic zone of a RGP lens can be measured with ....... | Radiouscope |
| An Enzyme contained in the precorneal tear film that protects the cornea from infections is.......... | Lysozyme |
| The layer of the precorneal tear film responsible for exchange of materials across the corneal surface is the | Aqueous Layer |
| how many layers does the cornea have? | 5 Layers |
| The average central thickness of the Cornea is....... | 0.56mm |
| the corneal epithelium obtains oxygen from the ....... | Precorneal Tear Film |
| The thickest layer of the cornea is the...... | Stroma |
| the corneal layer primarily responsible for maintaining the Cornea in a partially hydrated state..... | Endothelium |
| the Descemet's membrane of the cornea is produced by which layer of the cornea..... | Endothelium |
| Sever damage to the corneal endothelium results in what. | Corneal Edema |
| A tightly fitted soft contact lens can cause....... | Corneal Edema Limbal Compression |
| The Sclera of the eye is covered by what.... | Bulbar Conjunctiva |
| New blood vessels that grow into the cornea originate from blood vessels that are located in ......... | the Limbus |
| Obstruction of the flow of aqueous humor out of the anterior chamber results in... | Elevated Intra Ocular Pressure (Glaucoma) |
| a condition where the Iris or portions of the Iris in absent is called | Aniridia |
| the curvature of the central portion of the back surface of a contact lens is the...... | Base Curve |
| the central zone of a contact lens that contains the refractive power of the contact lens is the..... | Optic Zone |
| The measurement from one edge of a contact lens to the opposite edge is the..... | Chord Diameter |
| The base curve of a contact lens is also known as the ..... | CPC (Central Posterior Curve) |
| The Peripheral Posterior Curve of a bicurve Contact Lens is Steeper or Flatter than the CPC | Flatter |
| what happens to the sagital vault of the contact lens when a contact lens is steepened...? | it increases |
| shortening the base curve radius of a contact lens makes the lens steeper of flatter? | steeper |
| the problem of a loosely fitting contact lens can be solved by ordering a new contact lens having a ....................... Base Curve | Shorter (SSS) |
| Increasing the overall Diameter of a contact lens makes the lens steeper of flatter? | Steeper |
| The Effective power of a contact lens measured from the back surface is the............... | Back Vertex Power |
| This Contact lens has 2 different Radii on the anterior surface and a Spheric Posterior curve. It's used to correct Residual Astigmatism..... | Front Toric Contact Lens |
| When correcting Large amounts of Corneal Astigmatism a Toric lens must be used that is a ................. Toric. (Front/Back) | Back Toric |
| A contact lens that is used to correct both Corneal and Residual Astigmatism is ................ | Bi-Toric |
| A Contact lens with a thickened inferior edge that stabilizes the contact lens is called a............ | Prism Ballasted Contact Lens |
| A CTL that is Cut off inferiorly so the lower eyelid can help to stabilize the contact lens is called a ........... | Truncated CTL |
| A CTL that has a low wetting Angle has ............ Wettability | Good Wettability |
| Decreasing the overall diameter of a CTL will loosen or tighten the fit | Loosen the fit |
| A CTL having a BC radius of 7.94 mm fits too loosely, a tighter fitting CTL will have which one of the following BC.... (7.99 / 7.85) | 7.85 mm |
| a CTL having an overall diameter of 9.5mm fits too tightly, a looser ctl will have which diameter....... (9.6 / 9.3) | 9.3 mm |
| an instrument that's used to measure Corneal Astigmatism is..... | Keratometer |
| When the Vertical Corneal meridian is steeper than the Horizontal Corneal Meridian, the corneal astigmatism is...... | WTR With the Rule Astigmatism |
| Concerning measurements of Corneal Curvatures, the longer the mm of Radius the Larger of Smaller the Diopter value....? | Smaller (SSS Rule) |
| a CTL material having a large wetting angle is Hydrophobic or Hydrophilic? | Hydrophobic |
| A Lab Measurement of the Oxygen permeability of a RGP CTL is called...... | DK Value |
| A measurement of the Oxygen Transmissibility of a RGP CTL is called ........ | DK/L |
| The Greater the Central Thickness of a CTL the more of less Oxygen transmissibility?..... | Less |
| What is EOP? | Equivalent Oxygen Performance or Percentage Measures how much Oxygen actually reaches the Cornea while wearing CTL |
| A CTL designed with a peripheral carrier or Flange having no power and a Central Power Zone is called a ................ CTL | Lenticular Design |
| Is the Following K reading With the rule or against the rule astigmatism?.... 43.00@180/44.00@90 | With The Rule (more at 90) |
| The K-reading of the horizontal meridian of a cornea is 48.00, this is what mm of radius? | 7.03 mm (337.5 Rule) |
| Vertex Distance must be considered in determining CTL power if the Spectacle Rx is over................ D | +/- 4.00D |
| the BC of a rigid CTL sitting on a cornea is flatter than the corneal curvature. Therefore the Lacrimal Lens power is....... (plus/Minus) | Minus |
| the best type of slit lamp illumination to use for detecting gross corneal edema is called...... | Sclerotic Scatter |
| the type of slit lamp illumination that is used primarily for a general survey of the external eye is called...... | Diffuse Illumination |
| the type of slit lamp illumination that is useful for inspecting the anterior surface of a contact lens is called the....... | Direct Focal Illumination |
| if a person wanting CTLs has Blepharitis, you should do what? | refer them to the prescribing Doctor any type of "ITIS" has to go back to the DR. |
| where is the Giant Papillary Conjunctivitis Located?.... | on the Tarsal Plate of the Upper eyelid margin |
| a test used to assess the quality of the precorneal tear film is called the...... | BUT test ( Break Up Time) |
| Polymegathism of the corneal endothelium is thought to be due to ....... | Corneal Hypoxia |
| the type of slit lamp illumination used to observe Cells and flare in the anterior chamber of the eye is......... | Conical Beam Illumination |
| the type of slit lamp illumination that is the method of choice for examination of microcystic epithelial edema of the cornea is called.... | Retro Illumination |
| The best type of Slit Lamp illumination for studying the corneal endothelium is ...... | Specular Reflection |
| the Slit lamp light that passes through a cobalt blue filter can be used to observe.......... | Corneal Staining the Fit of the Contact Lens Corneal Dry spots |
| a Soft CTL case should be thoroughly cleaned at least........ | once per week |
| a Person with Scleral Show requires a (large/small) Diameter soft CTL? | Large Diameter Soft CTL |
| Preservatives in Contact Lens Solutions can cause .......... | Photophobia Corneal Staining Excess Tearing |
| What can occur during an allergic reaction to a CTL solution..... | Itching Conjunctival Redness Conjunctival Chemosis (Swelling) |
| True/False Corneal Sensation is reduced in an Aphakic Eye. | True |
| Giant Papillary Conjunctivitis occurs more frequently in people who wear what type of lenses.... | Soft Hydrogel lenses |
| wearing standard thickness soft CTL's longer than 12 hours per day for a prolonged period of time can cause............ | An increase in the steepening of the cornea Development of irregular astigmatism Permanent form of acquired Keratoconus |
| Limbal Compression is a sign of (loose - tight) fitted ctl | Tightly fitting CTL |
| an eye has a Spectacle Rx of -3.00-0.25X180. This eye should be fit with a soft CTL having a power of................ | -3.00 D (1/3 Rule) |
| an eye has a spectacle rx of -3.25-0.50X180. This eye should be fit with a hydrogel CTL having a power of........... | -3.25 D (1/3 Rule) |
| an eye has a spectacle Rx of -4.00+1.00X180. this eye should be fit with a hydrogel CTL having a power of........... | -3.50 D (1/3 Rule) |
| An eye has a spectacle Rx of -6.50+1.00X090. the K readings are 42.00@180/43.00@90. The Vertex Distance is 12mm. This eye should be fit with Soft CTL RX of,,,,,,,,,,,,,,,,,,,,,, | -5.25 D (1/3 Rule + 10.10.1 Rule) |
| what are characteristics of PMMA CTL's...... | Good Stability Good Optics Acceptable Wettability |
| which of the following CTL materials has the highest Oxygen Permeability.. (HEMA, PMMA, ACRYLATE, SILICONE) | Silicone |
| The water content of hydrogel contact lenses varies from.......... | 25% to 85% |
| The higher the Water Content of a Hydrogel CTL the.................... the Oxygen Transmissibility. | Greater |
| Hydrogel CTL are made of what material. | HEMA |
| Tears drain into the ........... | Punctum |
| During a blink the lower eyelid moves primarily towards the...... | Nose |
| The Muscle responsible for elevation of the upper eyelid is the........ | Levator Palpebrae |
| the PH of the Pre-corneal tear Film is...... | 7.35 |
| the layer of the pre corneal tear film that is responsible for exchange of materials across the corneal surface is the........ | Aqueous Layer |
| The Function of the Eyelids are......... | Limit the amount of light entering the eye Protect the eye from external irritation Distribute Tears over the surface of the eye. |
| The opening of the Meibomian glands are found on the...... | Eyelid Margin |
| the Meibomian Glands are located in the......... | Tarsal Plate. |
| an Acute infection of the Meibomian Glands is called..... | an internal Hordeolum |
| with spontaneous blinking, the normal blinking rate is...... | 12-18 per minute |
| the pre-corneal tear film is composed of how many layers....... | 3 Lipid, Aqueous, Mucus |
| with basic tear secretion, the aqueous tear film layer is secreted by the.............. | Glands of Wolfring and Krause |
| the pre-corneal tear film layer that changes the hydrophobic surface of the cornea to a hydrophilic surface is the .............. | Mucous Layer... |
| the pre-corneal tear film layer that reduces the rate of tear evaporation is the.......... | Lipid layer (oily) |
| The mucous layer of the pre corneal tear film is secreted by the..... | Conjuntival Goblet Cells. |
| The Lipid Layer of the Precorneal tear film is secreted from......... | the Meibomian Glands |
| A spherical PMMA CTL should be fit so that there is a slight............... | Apical Clearance |
| When fitting PMMA CTL, the CTL diameter can be calculated by adding 4 mm to the | Pupilary Diameter |
| A high minus RGP CTL should have .........(+/-) Carrier Lenticular Lenses. | Plus Carrier Lenticular Lens. Hyperflange |
| the quality of fit of a RGP CTL can be assessed with the use of........ | Fluorescein |
| Rigid CTL's can be modified in the office to become Steeper. (true-False) | False. |
| what solution improves the wettability of Rigid CTL's..... | Wetting Solution |
| if a rigid CTL on an eye is too steep the fluorescein pattern will show....... | Central Pooling |
| if a rigid CTL on an eye is too flat the fluorescein pattern will show....... | Central Touch |
| the size of the entire corneal cap can be measured with the.... | Topogometer |
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optician
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