Soft Contact Lenses – Materials, Manufacturing, and Screening Practice Test

These questions are part of the practice quiz. Start practicing

• What is a potential consequence of an eyelid condition on contact lens fitting?
• What percent of contact lens wearers experience dry eye with the lens wear?
• What factors of the eyelids determine vertical fissure width?
• Which pair of properties best describes filcon and focon lenses according to the material list?
• True/False: Contact lenses can be either charged or electrically neutral.
• Which conjunctival condition involves redundant conjunctival tissue causing folds?
• What are the advantages of a high modulus material?
• Which characteristic describes the material as chemically stable and physiologically inert?
• Which generation of SiHy lenses is described as being classified by phase separation and monomers and requiring plasma surface treatment?
• Which of the following is a soft lens disadvantage?
• The clarity of material; function of purity, chemistry, and hydration is described as what?
• Lathe cutting begins with input material in which form?
• The vertical fissure width (VFW) determines that a smaller/larger fissure needs a larger lens. Which is correct?
• How should we evaluate refractive information for a pre-fit contact lens evaluation?
• What is the one type of disposable contact lens?
• What anatomic measurements should be taken during the pre-fit examination?
• Which generation of SiHy is described as using macromers with no surface treatment of the internal wetting agent, and having lower oxygen permeability, high water content, and lower modulus?
• Oxygen transmissibility units include which term?
• What is the water content of a SiHy lens?
• Should athletes, performing arts, and those in public eye be considered for contact lenses?
• The higher the tensile strength, the more durable the lens is.
• Which eyelid condition is associated with eyelid margin dysfunction and relevance to pre-fit?
• In a silicone-based SiHy lens with reduced water content, which statement is true about oxygen availability?
• Holden-Mertz extended wear Dk/t?
• In spin casting, after the surfaces are formed, which process occurs that uses UV light to solidify?
• What is a primary overall advantage of SiHy lenses?
• Which charges on a contact lens are more attracted to positively charged deposits?
• Hydrogel/SiHy lenses have greater wettability compared with traditional hydrogels.
• Which statement about modulus and wearer comfort is true?
• What contact lens manufacturing method is what major companies use?
• Lower wetting angle indicates better wettability.
• FDA group 1 classification: Which description best fits Group 1?
• Baseline ocular health findings are part of what you should gather when evaluating contact lens suitability.
• What is the normal corneal diameter/white-to-white (WTW) measurement?
• Oxygen transmissibility can vary within the lens due to which factors?
• Which of the following is an operational advantage of soft contact lenses?
• Third generation SiHy is classified by macromers, no surface treatment of internal wetting agent, and has lower O2, high water, and lower modulus. Which generation does this describe?
• In a silicone-dominant SiHy lens, increasing water content leads to which change in oxygen availability?
• FDA group 5 classification: Which description best fits Group 5?
• How does hydrogel interact with water?
• Which group binds water or increases oxygen permeability in contact lenses?
• Which statement best describes how wettability relates to comfort?
• Pupil diameter during the pre-fit examination is measured in which lighting conditions?
• Which wearing schedule allows wear up to 30 days before removal?
• Pupil diameter helps determine which aspect of contact lens design?
• With increased water content, absorption of tear solutes ______.
• Hydrogel lenses are now made of which material?
• Which numerical blur value is associated with spherical aberration in contact lenses?
• Hydrogel lenses are now made of which material?
• Lid wiper epitheliopathy is evaluated to assess tear film distribution along which area?
• By polymerizing different combinations of monomers, ____________ and _____________ properties of the lens can be created.
• Which factor is not a primary determinant of a lens's oxygen permeability?
• Why is it important to watch for ectropion or entropion/trichiasis with slit lamp examination?
• What soft contact lens material has a low modulus?
• In terms of durability, how do hydrogel lenses compare to SiHy lenses?
• The ability of a contact lens to keep its shape when subjected to stress and its resistance to deformation; 'stiffness' of the lens is described by which term?
• Which tear film property is most associated with improved visual acuity in contact lens wear?
• Increasing water content in a hydrogel lens has what effect on its refractive index?
• Which characteristic describes the lathe cutting method?
• Soft contact lenses are best described as what type of lenses?
• What are the building blocks of contact lenses?
• Which FDA group has high water content and ionic polymer?
• For new contact lens wearers, which combination is suggested?
• What is the most important aspect to consider if someone wants contact lenses?
• With increased water content, oxygen transmissibility for hydrogels generally ______.
• Which characteristic describes the lens's resistance to spoilage and deposits?
• Which statement about replacement schedules is true?
• During slit lamp examination, what should you particularly assess when eversing the lids?
• Pilots and flight attendants should be considered for contact lenses?
• Which FDA group has low water content and nonionic polymer?
• Which option describes a method to reduce friction by modifying the lens surface?
• How much a contact lens can be stretched before it breaks is called what?
• Which item is considered an ocular history question to ask a contact lens wearer?
• Spin casting curing uses which energy source?
• Which option lists the four wearing schedules defined by the FDA?
• What timing is advised for topical medications before wearing contact lenses?
• What is considered a large pupil diameter?
• Which of the following is a medical history question to ask a contact lens wearer?
• What term is defined as weight of water divided by weight of hydrated gel x 100?
• Why wait to perform vital dye staining until after contact lens fitting?
• Which statement best describes the relationship between friction on the lens surface and comfort?
• Which generation is classified by monomers and macromers, requires no surface treatment, and uses PVP as a wetting agent?
• Higher order aberrations are not eliminated by contact lens wear.
• How does decreasing water content in a hydrogel lens affect oxygen availability?
• What are the disadvantages of a high modulus material?
• Which lens type typically has higher water content, leading to a lower refractive index?
• FDA group 2 classification: Which description best fits Group 2?
• Review: Most hydrogels have ______ water content, whereas SiHy lenses have ______ water content.
• What is MRD1+MRD2 equal to?
• Out of the five FDA classifications, which groups are most likely to attract deposits?
• The term used to describe how lubricious the surface of a contact lens is (its resistance to friction with the lid) is:
• Cast Molding: With cast molding, the liquid polymer is cured with a _____ light.
• Which statement correctly identifies the cross-linking agent used in early hydrogel lenses?
• Which statement about silicone lenses is true?
• Which process adds stability to contact lens materials?
• Cast Molding: Remove the lens and _________.
• Which generation is characterized by monomers and macromers, with no surface treatment required and PVP as a wetting agent?
• During slit lamp examination, which conjunctival sign should you watch for?
• Which FDA classification corresponds to silicone hydrogel soft contact lenses?
• What are the disadvantages of a low modulus material?
• Spin casting curing uses which type of light?
• What does corneal diameter/white-to-white (WTW) determine?
• What are the three history considerations we must include when fitting contact lenses?
• What term describes the blink's ability to spread tear film across the anterior surface of a contact lens?
• Lathe cutting yields lenses cut into which shapes?
• Which tear film parameter measures the salt concentration of the tear film?
• Which statement about soft contact lenses is true?
• Which notation is used to express Dk/t magnitudes like 24 x 10^-9?
• With increased water content, index of refraction ______.
• The lathe cutting method is best suited for which production scenario?
• According to the improvement trends, how does modulus change for SiHy materials as they improve?
• In spin casting, the front surface is determined by what?
• Who invented spin casting?
• What is a common modulus value for a silicone/hydrogel lens?
• How should we measure binocular vision status for a pre-fit contact lens evaluation?
• What does White-To-White (WTW) stand for in pre-fit measurements?
• Oxygen permeability is inherent to the material.
• What describes many monomers polymerized together?
• Clear/non-tinted contact lenses transmit ______% of light.
• What is the primary purpose of the HVID measurement in pre-fit testing?
• Why is the lathe cutting method not commonly used?
• How does increasing modulus affect the stiffness of a contact lens?
• Water content can influence which properties?
• Spin casting yields what edge characteristic?
• Which manufacturing method uses a master mold for every combo of power, base curve, and diameter?
• With spin casting, a faster speed creates a steeper curve.
• Which of the following is information to gather when evaluating if a patient is suitable for contact lens wear?
• With better wettability, are deposits on the lens more likely to form?
• After injection into the spinning mold, which process solidifies the lens?
• Which statement best describes first-generation SiHy lenses?
• Which method is cost effective for high-volume manufacture?
• Which statement describes oxygen transmissibility for hydrogel and SiHy lenses?
• In SiHy lenses, which property is described as being resistant to dehydration?
• Which property describes a lens surface that is easy to wet and feels smooth against the eye?
• Which list correctly reflects the steps of lathe cutting?
• SiHy lenses have what relative water content compared to hydrogels?
• Which statement lists the cons of silicon lenses?
• What is the term for a large monomer used in polymerization?
• What was the first method employed for soft lenses?
• Which step is performed last in the lathe cutting process?
• Which wearing schedule allows wear up to 7 days and 6 nights before removal?
• Oxygen permeability is dependent on which properties of the material?
• How can a 'bad' pre and post lens tear film lead to discomfort?
• In this context, what does the symbol D represent?
• Which characteristic describes ease of manufacturing and cost effectiveness?
• What is a con of silicon/hydrogel (SiHy) lenses?
• What happens if the cornea does not receive oxygen?
• How can we measure a patient's corneal shape?
• Which of the following is a soft lens advantage?
• Should those who work in dirty environments be considered for contact lenses?
• Based on the stated improvement trends, how is wettability expected to change in SiHy lenses?
• A low contact angle indicates what about wettability?
• Which statement describes wettability of hydrogel and SiHy lenses?
• Which of the following is used as subjective dry eye assessment?
• How should visual acuity be measured for a pre-fit contact lens evaluation?
• Holden-Mertz daily wear Dk/t recommendation?
• What are the three major components of a pre-fit contact lens examination?
• Which statement best describes what TBUT assesses?
• Which dye is listed as a vital dye used in tear film assessment?
• Spin casting tends to decenter in which direction?
• After curing in spin casting, what are the next three steps?
• Which FDA group has low water content and ionic polymer?
• From which sources does the cornea receive oxygen?
• How much blur can spherical aberration cause?
• Which statement is true about hydrogel lenses?
• Which item is NOT part of the anatomic measurements taken during the pre-fit examination?
• What are the pros of silicon/hydrogel (SiHy) lenses?
• What are the two types of replacement schedules for contact lenses?
• Oxygen transmissibility can vary across a lens with changes in which factors?
• What are the pros of cast molding?
• Which lids and lashes conditions should we watch for during slit lamp examination?
• Which property indicates the material is able to transmit light clearly without distortion?
• Oxygen transmissibility is related to which property of the lens?
• Silicone hydrogels are categorized as Group 5 by the FDA.
• Pinguecula or pterygium are conditions involving which ocular surface structure?
• Which of the following are the three history considerations to include when fitting contact lenses?
• What are the advantages of a low modulus material?
• Which issue is more common with high modulus lenses?
• The FDA has classifications of soft lens materials.
• What was the first soft lens material used?
• Which method was the earliest used to manufacture soft contact lenses?
• Which material is typically associated with a high modulus?
• Between hydrogel and silicone contact lenses, which tends to have the lower refractive index?
• When should you determine a patient's prescription for a pre-fit contact lens evaluation?
• FDA group 4 classification: Which description best fits Group 4?
• Which option correctly lists the four FDA defined wearing schedules for contact lenses?
• How is corneal diameter/white-to-white (WTW) measured?
• What is the most common reason people stop wearing their contact lenses?
• In spin casting, the liquid polymer is injected into a ________ ___________.
• What are the pros of spin casting?
• Contact lenses are made up of which materials?
• What does HVID stand for in pre-fit measurements?
• Which generation of silicone/hydrogel lenses is characterized by phase separation and monomer composition, requires plasma surface treatment, and exhibits high oxygen permeability, low water content, and high modulus?
• What is the oxygen transmissibility (Dk/t) of a hydrogel lens?
• With increased water content, pore size ______.
• Which modulus is associated with better corneal draping?
• Which statement describes the coefficient of friction for hydrogel and SiHy lenses?
• Which of the following is NOT listed among medical history questions for contact lens wearers?
• Which of the following is listed as a pro of hydrogel lenses?
• Which corneal finding indicates vascular growth into the cornea?
• How are contact lenses bound?
• Select the methods that can lower the coefficient of friction on a contact lens surface.
• Which type of contact lens has the greatest wettability?
• What is the water content of HEMA alone?
• With spin casting, a slower speed creates a flatter curve.
• What is the vertical fissure width (VFW)?
• Why does better wettability improve visual acuity?
• A lower coefficient of friction on a contact lens results in:
• Which Dk/t value is associated with Holden-Mertz's extended wear recommendation?
• What is the oxygen transmissibility (Dk/t) of a SiHy lens?
• Which measurement best describes wettability of a contact lens?
• Which statement best describes the effect of a higher Dk/t value on oxygen transmissibility?
• During the pre-fit examination, which anatomical regions should be evaluated with the slit lamp?
• HEMA alone has a water content of 38%. Which of the following values would be correct for that statement?
• Which term best describes a lens's stiffness under mechanical stress?
• Which item is considered an ocular history question for contact lens wearers?
• Two monomers polymerized together are called
• Contact lenses can improve vision in which condition?
• Which of the following is a valid planned replacement interval for contact lenses?
• Which property decreases with higher water content?
• Which is a common reason a patient may want contact lenses?
• Which of the following is listed as a con of hydrogel lenses?
• What is the water content of a hydrogel lens?
• Which of the following is a pro of silicone lenses?
• In SiHy lenses, which properties are provided by the hydrogel portion?
• What are the cons of spin casting?
• Harvitt-Bonanno daily wear Dk/t?
• Which statement is true about hydrogel lens water interaction?
• The higher the tensile strength, the easier it is to clean and insert without tearing.
• In spin casting, which surface is determined by the mold?
• Which property tends to increase with higher water content, aside from pore size?
• Which component provides oxygen permeability and optics in SiHy lenses?
• Which statement correctly describes oxygen availability when water content increases in hydrogel vs silicone-dominated lenses?
• Harvitt-Bonanno extended wear Dk/t?
• Which aberration can be observed as glare, blur, and halos when wearing contact lenses?
• A lower modulus results in a contact lens that is:
• Which characteristic refers to maintaining stable dimensions and parameters?
• Which tear film parameter would you use to assess tear film stability by measuring the time until breakup?
• Which statement correctly describes the modulus of hydrogel lenses compared with SiHy lenses?
• The higher the Dk, the better the oxygen permeability.
• Which statement describes a property of hydrogel lenses regarding water?
• Should lab workers be considered to wear contact lenses?
• Increased wettability improves deposit resistance on the contact lens surface.
• What does the symbol K represent in this context?
• Which charges on a contact lens are more reactive in an acidic solution?
• Which statement best describes the general comparison of Dk/t between hydrogel and silicone hydrogel lenses?
• How does better wettability relate to visual acuity?
• Hydrogel lenses originally were made out of which combination?
• Which type of modulus is associated with fewer edge-related problems?
• High water content hydrogel lenses are typically:
• What are the three types of planned replacement contact lenses?
• True or False: It is important to check entering VAs during any eye exam.
• Low wettability is expected to result in which effect on comfort?
• Which anatomical region is NOT typically evaluated with the slit lamp during the pre-fit examination?
• What term describes the ratio of the speed of light in air to the speed of light in a material?
• Which statement correctly describes the effect of refractive index on refraction?
• What is considered a small pupil diameter?
• How does increasing water content in a hydrogel lens affect oxygen availability?
• Which factors influence vertical fissure width and potentially lens decentration risk?
• With increased water content, strength ______.
• Which statement describes the water content category of SiHy lenses?
• The ability of a contact lens to allow oxygen to reach the eye by diffusion is called:
• In early hydrogel lenses, HEMA monomers were cross-linked with which agent?
• Which of the following describes a hydrogel lens with high water content (>60%)?
• Which Dk/t value is the highest among the listed extended wear recommendations?
• A lower wetting angle is better.
• FDA group 3 classification: Which description best fits Group 3?