Quiz Questions Week 1 -5 Flashcards
During a routine contact lens exam, you notice the patient has a Dellen. What would be one cause?
GP lens rubbing on the limbus
During a contact lens evaluation, it is observed that the patient has superficial punctate staining. What is one cause?
Improper use of hydrogen peroxide solution
The patient presents with the inward turning of the eye. Name one specific cause.
Trauma to the eyelid
During thr contact lens examination, the optician notices staining at the inferior 6’oclock position. What is one specific cause for this staining?
Incomplete blink meaning the tear film is not spreading over the cornea properly.
What is one cause of ancanthameba?
swimming/showering in contact lenses
During a slit-lamp examination, it is observed that this patient has corneal edema. What is one cause?
Overwear like sleeping in cls that causes hypoxia
What is one CAUSE of dry eye?
aqueous deficiency?
What is one SIGN of dry eye observed by the practioner?
3 o’clock and 9 o’clock staining
A tear prism of 3mm or higher could be indicative of……….
Plugged punctum
Corneal Hypoxia is……………..
Oxygen deprivation of the cornea
Reduced sensitivity of the cornea could be the first sign of…………..
Hypoxia
What is meant by DK value?
Oxygen permeability
What is the medical term for ‘bulging eyes’ due to thyroids?
Exophthalmos
Another term for ‘excessive tearing’ is……….
Epiphora
If a patient presents with contact lens overwear one of the symptoms observed in a slit lamp will be………..
Corneal Vascularization
If a patient presents with entropian it means ……….
Eyelids are turning inwards
Sclerotic scatter is used to look for…………….
Edema
What is the first assessment done during a contact lens fitting?
Visual Acuity
Which slit lamp illumination requires the beam to be in the shape of a small circle?
Conical Beam
Using disposable contact lenses more than one time falls under the compliance category. T/F
TRUE
………………. slit lamp illumination is used to look at the tear film.
Specular Reflection
Which one of the following options is NOT a treatment for dry eyes?
1- Blinking exercises
2 - Fluorescein installation
3 - Warm Compresses
4 - Artifical tears
2 - Fluorescein Installation
Which slit lamp illuminations detects aqueous flare?
Conical Beam
What equipment is used to measure the curvature of the corneal apex?
Keratometer
A contact lens fitter gives brochures to the client to store their contact lenses. What component of SOAP is this?
Plan
A contact lens fitter determines the contact lens has good movement. What component of soap is this?
Assessment
When you are collecting information on the types of medication that the client is taking this would be considered a/an ……………….
Subjective assessment
When you perform a keratometry assessment on a patient this type of assessment would be considered a/an …………..
Objective assessment
When taking k readings you get the following prescription: OD:45.50/47.00@090. Is this WTR or ATR?
WTR
The keratometer reading is Clear Blurry Clear, what type of fit does this indicate?
Flat fit
Which one of the following reasons is not an important part of the preliminary assessment when assessing tears during contact lens fitting?
1 -Predict potential success of a client
2 -Eliminate likely failures
3 -Discover marginally dry eyes which would be adversly affected by contact lenses
4 -Ensure these is no GPC
4 -Ensure these is no GPC
When a patient reports symptoms, they generally fall into three broad categories? What are they?
Appearance of the eye
Ocular Discomfort
Poor Visual acuity
Name 3 indirect illuminations
Retro illumination
Indirect Proximal illumination
Sclerotic scatter
If a patient is told to throw away there lens every 14 days. This is known as………
Modailty - a way to use them
…………………(soft
cl material) lenses are generally the number one lens of choice.
silicone hydrogel
Which of the following is NOT a contact lens recommendation for high prescriptions?
1- silicone hydrogel
2- large diameter
3- high oxygen permeability
4-low water content hydrogel
4 - low water content hydrogel lenses
Axial myopia occurs when……
the eyeball is too long
Spherical equivalent lenses should only be used in place of a toric lens when the astigmatism is less than ………… dioptres.
-0.75D
How are hard lenses manufactured?
Lathe cutting
Prism ballast lenses work on a stabilization technique that ………… the bottom of the lens.
weights
Extended wear lenses can be worn up to how many nights in a row before removing them?
6 nights
Surface wettability can be assessed with a ……………..
keratometer
To check the back vertex power of a lens it is done with a ………..
lensometer
What is the most common manufacturing process of soft contact lenses?
cast molding (injection molding)
When checking the fit of a toric lens you notice the lens is rotated 20 degrees clockwise. The orginal trial was -1.00 -1.25 x 100. What would the new lens power be?
-1.25 -1.00 x 120
Lenses that are occassionally slept in overnight can be classified as……………
flexible wear
Soft contact that start as a rod or button of material are manufactured using the ………… process.
Lathe cut
What is the stabilization design called when a lens is sliced flat at the bottom?
truncation
Which lens stabilization design uses a minus carrier lens?
peri ballast
This lens may appear well-fitted and comfortable initially but after several hours of wear there may be discomfort. The lens may also have minimal movement. What should the contact lens fitter do?
flatten the base curve as the lens is too tight/steep
Silicone hydorgel are more rigid than hydrogels and therefore are easier to handle. T/F
TRUE
Hydrogel lenses have higher oxygen permeability then silicone lenses. T/F
FALSE
Hydrogel lenses are hydrophobic. T/F
FALSE
When a toric lens is rotated to the right you would add the degree of rotation to the current axis to compensate. T/F
FALSE - the marking is to the right so counter clockwise - LARS - RIGHT SUBTRACT
A dry eye patient would benefit from HEMA hydrogels lens with a high water content. T/F
FALSE
Environmental and task factors can affect lens dehydration. T/F
TRUE
Thin lenses are less prone to dehydration and easier to handle for minor degrees of myopia. T/F
FALSE
What are two things that can be done to improve a loose fitting lens?
-Keep the BC the same and choose a larger diameter
-Keep the diameter the same and steepen the BC
When assessing a soft contact lens in relation to lens movement, what are the 4 checks that a CLF should perform?
Upward gaze
lateral gaze
push up test
Blinking
Which equipment is used to measure the diameter of a gp lens?
a V-gauge
Which equipment is used to measure the BC of the lens?
Radiuscope
What is the disadvantage of using PMMA lenses?
oxygen permeability
If a gas permeable lens is too thin the following can occur…………..
lens flexure
Adhesion to the cornea in a rgp indicates what probably cause?
steep fit
A person wearing a RGP lens complains of the following symptoms, loss of vision nd comfort. What is one probably cause?
scratches on lens
Which measurement affects the lens to cornea fitting relationship?
BC - base curve
A slit lamp can be used to assess the edge of the gp lens. T/F
TRUE
You are given the following K’s: 43.50/44.50 @ 090 and asked to fit the k meridian at 43.25. What would you do to the lens?
add plus power
Needing a lower DK lens is a good reason to switch to a gas permeable lens. T/F
FALSE
The following statement that the back lens power increases by +0.25 for each 0.05mm that the BOZR is steeper than the cornea. The over-refraction will therefore need to be -0..25D greater. T/F
TRUE - understand the logic reread
What is the purpose of preservatives in cls solution?
restricts growth of microorganisms
Alcohols, such as isopropyl may be incorporated as a preservative in cleaning solutions. Is this statement true?
YES
What agent improves the wetting time and comfort of the solution?
viscosity agent
What is preservative free saline used for? 2
-mainly for rinsing
-heat disinfection
Fitting scleral lenses decreases mucus build up. T/F
FALSE -mucus accumulates especially at the start
A therapeutic tinted lens is designed to…….
treat an underlying defect or disease
What is a purpose of a prophylactic tint?
prevent injury or disease of the eye
Another name for a comfort drop is dual surfactant. T/F
FALSE
Acanthamoeba is a …………………
type of bacteria that can cause vision loss
What is the primary indication of scleral lenses?
1- keratoconus
2 - vascularization
3 - children
4 - seniors with prebyopia
1-Keratoconus
What is the purpose of fenestration?
to help with tear exchange
A coloured lens can alter surface chemistry of a lens which can …………
reduce wettability
What is the main factor that causes corneal swelling when wearing a lens overnight is……………
hypoxia
In you children cls can be useful to manage different ocular motility disorders such as nystagmus. T/F
TRUE
Silicon rubber lenses are used in correction of refractive error in…………
young children
When a person has reoccurring corneal erosion. They may be fitted with…….
bandage lens
What 2 methods can be used for disinfections?
heat
chemical
What are two changes that have known to occur on the cornea with EW lenses?
epithelian cell changes - dry eye
hypoxia due to restricted amount of oxygen to the cornea - vascularization/edema
