Download Contact Lens Registry Examination: Review Questions and Answers and more Exams Optics in PDF only on Docsity!
National Certification Organization
for Opticians
The National Contact Lens Examiners
(NCLE) ABO American Board of Opticianry
CLRE Contact Lens Registry Examination
Course Title and Number: ABO NOCE Competency Exam Exam Title: Registry Exam Exam Date: Exam 2025- 2026 Instructor: [Insert Instructor’s Name] Student Name: [Insert Student’s Name] Student ID: [Insert Student ID]
Examination
180 minutes
Instructions:
- Read each question carefully.
- Answer all questions.
- Use the provided answer sheet to mark your responses.
- Ensure all answers are final before submitting the exam.
- Please answer each question below and click Submit when you have completed the Exam.
- This test has a time limit, The test will save and submit automatically when the time expires
- This is Exam which will assess your knowledge on the course Learning Resources.
Good Luck!
🤔 Hybridgrades101@gmail.com
Ctrl + Click ✅ORDER NOW ✅ Follow
Link
& Get Instant
Expert Help
NCLE - CLRE Basic Contact Lens Exam Review Questions and Answers | 100% Pass Guaranteed | Graded A+ | 2025- The National Contact Lens Examiners NCLE ABO American Board of Opticianry CLRE Contact Lens Registry Examination
Read All Instructions Carefully and Answer All the
Questions Correctly Good Luck: -
Base curve Radius of curvature on the back central surface of the contact lens Blend curve the treatment given to the sharp junction between the secondary and peripheral curve to eliminate sharp edges due to abrupt changes in the curvature; it can be light, medium, or heavy and it is typically equal to the average radii of the secondary and peripheral curve. Peripheral curve Outermost curve on the back surface of the lens that is designed to prevent the lens from pressing on the lumbar area of the curve and enables it to move when the eye blinks. Center Thickness (c.t.)
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 ORDER NOW 🤔
🤔 Hybridgrades101@gmail.com Decrease in edge thickness-good for high minus lenses to limit lid interaction or to lower a high riding lens;known as hyper flange To increase edge thickness, order a flatter radius in relation to the base curve To decrease edge thickness, order a steeper radius in relation to base curve Lens edge- junction between the front and the back surface of the lens Anterior zone-touches the lid and it is designed to minimize lid irritation Posterior zone-small reverse curve on the back surface to push the edge away from the surface of the eye; helps maintain centration and allows movement of the lens during blink. Apex-where the two zones meet and should be sufficiently rounded. Lens power- Measured as the difference between the radii of the front and back surface Prism ballast- Larger addition of base down prism to the bottom of a lens that helps orient position for specialty lenses such as translating bifocal designs and Toric lenses. Sagittal depth Distance from a flat surface and the central back surface of the lens Spherical curves
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com Radius of curvature is the same along every meridian along the back surface and the front surface of the lens. Truncation Removal of a portion of the lens so that it can aid in orientation, good for front Toric and bifocal lens designs. Effective power formula Du= Dk/ 1-Dk*d Du: vergence at an unknown point in meters (diopter ) Dk: vergence at a known point in meters (diopter) d: distance between points (5cm to 0.05) index of refraction n=speed of light in air (186,000)/ speed of light in selected material n=186,000/132,000=1. Axial length of eye Corneal thickness (.5mm)➡posterior cornea to anterior crystalline lens (3.1mm)➡crystalline lens thickness (3.6mm)➡posterior crystalline lens to retina(17.2mm)➡total axial length of eye (24.4mm) Magnification formula m=1/1-Dd m: magnification D: lens power (diopter) d: vertex distance + 3mm (3mm is the distance from the edge of the backside of the cornea to the pupil) Example: figure the magnification of a spectacle lens of a
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com Step one: D1=1.49-1.00/0. = +75.97D n1 (index of air) Step Two: Determine power of back surface. 1.00-1.49/0. = -62.98D Step Three: Use the formula for back vertex power. Dbv = D1/1-D1*d/n +D2= 75.97/ 1-(75.97)(0.00039/1.49)+ - 62.98= 14.53D d= the thickness of the contact lens Lacrimal Lens The natural tear lens that is created between the cornea and contact lens The cornea is clear and must remain clear, which means that it must be_______and have regular cell structure, and be free from _________.
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com Avascular, scarring The layers of the cornea from the outermost layer to the innermost layer in order are: Epithelium Bowman's layer Stroma Descemet's membrane Endothelium In a normally healthy eye, minor corneal abrasions of the cornea are generally repaired within______hours by mitosis and migration of fellow cells. 48 (hours) Which layer of the cornea does NOT regenerate after injury? Bowman's layer Enlargement of endothelial cells is called___________. Polymegathism Keratometry measures the central ________ of the cornea. 3mm You can extend the range up to 61D by placing a ________ trial lens over the aperture closest to the patient. This extends up an additional _________. +1.25D, 9.00D The ___________ is the transitional zone from clear, avascular cornea to the opaque sclera. Limbus The aqueous layer, which is the middle layer of the tear film, contains________
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com True On the lids, the conjunctiva is referred to as the ____________ , while on the globe of the eye, it is referred to as the _______. Palpebral conjunctiva, bulbar conjunctiva. The refractive index of the cornea is:
Inflammation of the conjunctiva is called: conjunctivitis Symptoms of the inflammation of the conjunctiva include: Pain, photophobia (light sensitivity), impaired vision, and discharge. Eyelids are termed the________ while opened, and they are __________. Palpebral aperture, not always the same size. The ___________ pumps tears away. levator muscle ______________ is an eyelid that is turned inward, and is often a result of muscle spasm in the lid or scarring from trauma. Entropion Under corneal stress, blood vessels may be seen to grow into the cornea in the area called the limbus. The blood vessel growth is called: Neovascularization Crystalline lens is ___________ that continues to add layers throughout life. An onion- like structure
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com The __________ are two thin, elongated plates of dense connective tissue, about 2.5cm. In length; one is placed in each eyelid and contributes to its form and support. Tarsal plates The fleshy caruncle is located at the________. Inner canthus The retina is connected to the brain by the ________, which is not a true nerve, but tract. Optic nerve Cones provide_________ and are more numerous in the _________. Detail, macula There are three categories of cones- according to __________. One is the most sensitive to short wavelength (________), one is most sensitive to __________, and one is most sensitive to ___________. Photopigments, blue, green, red The iris is a thin vascular membrane, averaging about ________mm horizontally and _______mm vertically. 11/12, 9/ The pupil is controlled by the ___________ muscles. Sphincter and dilator A difference in pupil size is called: anisocoria The choroid is located between the _________ and the_______. Retina, sclera ____________ is the result of the increased fluid pressure in the eye due to the reduction or blockage of aqueous drainage. glaucoma
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com What is the syndrome that causes a dry eye mainly found in the inferior cornea resulting from insufficient tear secretion? keratitis sicca Symptoms of ________ include photophobia, hazy vision, red eye, reduced comfort on lens removal, light halos and reduced CL wearing time. Corneal edema ________________ are both viruses that once introduced, remain in the body. Herpes and HIV An infection often resulting from contaminated water from distilled water, homemade saline, rivers, lakes, ponds, oceans, well water, hot tubs, and pools is ___________. Acanthamoeba An example of With the Rule Astigmatism is: -2.00 -2.00 x 180, 42.00 @180/ 44.00@ An example of residual astigmatism is: -2.00 -2.00 x 180, 43.00 @180/ 44.00@ Both anisometropia and antimetropia may result in the condition whereby two unequal images are sent by the eyes to the brain, and it is more prevalent due to refractive surgeries. The condition is called: Aniseikonia At what power do we need to compensate for vertex distance? For spectacles, when the power is over _________ and for contact lenses, when the power is over______. +/- 7.00, +/- 4.
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com Using the conversion factor, if the keratometry readings are 45.00D the radius of the curvature would be: 7.50 mm The slit lamp is also referred to as a: Biomicroscope ____________ uses the widest slit, longest aperture. The light source will be positioned at an angle of 40°-50°. It is used to view overall area, to observe the ocular adnexa, cornea, sclera, lids, conjunctiva, lens surface, and also lens fitting characteristics. Diffused Illumination What is probably the most useful and important illumination that you will use on the slit lamp? direct illumination We have an expert-written solution to this problem! Which slit lamp illumination is used to observe the layers of the cornea? Direct illumination / optical section To create __________ , the observer uses a focused parallelepiped placed out-of-clic directed at the limbus. Sclerotic scatter The _____________ is used to assess fluorescein staining. cobalt blue filter When an observer is using a slit lamp and is in focus, there should be _______ of the slit when the illumination system is
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com In fitting a contact lens, if the fitter fits a lens on "K" that means: The lenses are fitted to parallel the flatter meridian of the cornea. A contact lens that is fit steeper than "K" will: Produce a plus lacrimal lens, and possibly be tight Given the K's 42.00@180/43.00@090, a good CPC (base curve) would be:
Given the K's 42.50@180/45.00@090, a good CPC (base curve) would be:
Given the K's 42.50@180/ 46.75@090, a good CPC (base curve) would be: A. 44. B. 45. C. 42. D. None of the above Answer is “D” none of the above Given the K's of 42.00@180/ 43.00@090, a CPC of 42.50, and a manifest Rx of -1.00 -1.00 x180, what actual lens power would you order? -1. If the diameter is kept constant and the base curve is changed, the sagittal depth of the lens changes. Therefore: The steeper the base curve, the larger the sag, and the steeper the fit.
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com For calculation purposes, the wearing vertex of contact lenses is ___________ mm. 0 Given an Rx of -11.00 sphere, refracted at Vtx. 14mm, please calculate the compensated power for a gas permeable lens. -9.50D Du= Dk/1-Dkd Du= -11.00/1-(-11.000.014)=-9.53 or -9. Given an Rx of +11.00 sphere, refracted at Vtx. 12mm, please calculate the compensated power for a gas permeable lens. +12.37D A contact lens that has two different and perpendicular radii of curvature on both its anterior and posterior surfaces is a __________ lens. Bitoric Given the manifest Rx of -2.50 -2.00 x 180, and K readings of 44.50@180/46.50@090, please determine Delta K, and then determine the CPC of the lens. Delta K is 2.00/ CPC is 45. With an Rx of -4.75 -2.50 x 180, and K's of 42.25@180/ 42.75@090, which of the following lens types would you fit on the patient? Front surface Toric GP Given the following diagnostic lens, and an over refraction of -1.00 -1.50 x 175, what final lens would you order if the lens centered well? BC= 42.
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com Cobalt filter Fluorescein temporarily stains tears but will not stain________ since the fluorescein is a water-soluble molecule that doesn't penetrate intact lipid cell membranes. Intact epithelial cells The depth of the tear layer under the lens can be evaluated by color. The deeper the layer of tears, ________. The less the tear layer ________. The brighter the fluorescent green color, the less fluorescent green and area appears darker This fluorescein pattern indicates a __________ lens-cornea relationship. Steep This fluorescein pattern indicates a ________ lens-cornea relationship. Flat This fluorescein pattern indicates ______ staining pattern. With-the-rule astigmatism
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
🤔 Hybridgrades101@gmail.com This fluorescein pattern indicates a _________ staining pattern. Against-the-rule astigmatism Given the position of the inferior lid in relation to the lower limbus, which design of multifocal contact lens would you suggest? Aspheric Given the K's 42.00@180/42.50@090, and manifest Rx of -1. -0.50 x 180, and your patient wants to wear their lenses only on the weekends, which lens type would you suggest? Soft spherical People who are heavy surface depositors may benefit from the use of: Daily disposables lenses A soft lens should have a curve and diameter that will allow it to: Drape the cornea, and vault over the limbus and extend approximately 1.0mm onto the sclera. To do a spherical equivalent: Take half of the cylinder and algebraically add it to the sphere power, vertex as necessary and that is your beginning power.
Need Writing 🤔Help? We've Got You Covered! ✍
100% NO A I or Plagiarism Guaranteed🤔
