Week 5 - Quiz Revision Flashcards
What is the primary purpose of handling tints in contact lenses?
to make lenses easier to locate during handling
Cosmetic tinted lenses are primarily used for………
enhancing or changing the eye’s colour
Which type of tinted lens is used to mask corneal scarring or to make a disfigured eye appear more typical?
prosthetic tint
Performance-enhanced tinted lenses, such as X-chrome lenses, are used to…….
enhance color vision in color-deficient patients
Who would be an ideal candidate for prophylactic tinted lenses?
patients exposed to intense sunlight/UV
Which type of tinted lens is often hand-painted for custom theatrical effects?
theatrical tint
Therapeutic tinted lenses are primarily designed to……….
treat underlying defects or diseases
Which condition could benefit from therapeutic tinted lenses to reduce photophobia?
achromatopsia
What is a key characteristic of prosthetic tinted lenses for non - sighted eyes?
they have a painted iris and opaque pupil
A tinted contact lens can improve vision in low light conditions. T/F
FALSE
What condition is associated with reduced oxygen supply to the cornea in extended wear cls?
Corneal Hypoxia
What symptom should patients monitor for as an early sign of potential cl complications?
sensitivity to light
How is flexible wear best described?
intermittent use of cls overnight and during sleep
What is the primary advantage of frequent replacement lenses in extended wear?
reduced exposure to accmulated protein deposits
Which adverse effect is specifically associated with the use of higher modulus, first-generation silicone hydrogel lenses in extended wear?
unwanted orthokeratology
What is a common ocular response when a patient first wears RGPs lenses?
narrowing of the palpebral aperture
What is the preferred type of lens for patients with severe drye eyes?
scleral lenses
Which condition is a medical indication for cl usage?
keratoconus
What are two common contraindication for cl wear?
poor hygiene and compliance
What should a px do if they experience difficulty removing their cls after showering?
use artificial tears and keep the eyes closed for one minute before trying again
If a px presents with bilateral superficial punctate keratitis (SPK) and mild irritation at their one - month follow up, what is the most likely cause?
solution sensitivity
What type of cl is often best for correcting corneal irregularities?
RGP lenses
Which of the following is NOT a recommended action for a patient experiencing non-wetting of a rigid lens?
1-increase the lens replacement frequency
2- polish the lens to remove deposits
3- use protein-removing agents
4-stop wearing cls permanently
4- stop wearing cls permanently
Which environmental condition might contraindicate cl use?
working in a lab with chemical fumes
What is the primary function of a scleral lens?
To create a tear-filled vault over the cornea
What materials are commonly used for scleral lenses to ensure high oxygen permeability? 2
Acuity 200
Boston X02
What cl is designed to deliver medication directly to the eye’s surface?
Medicated lenses
In fitting of multifocal cls which factor is crucial for successful adaptaion?
pupil size
What is a primary consideration when using distance powered cls with reading glasses for presbyopia?
they should be used intermittently rather than continously
What should be checked to ensure a well-fitting scleral lens? 2
movement and rotation of the lens
What is a popular substance found in preservatives?
isopropyl (alochol)
What does isopropyl do to a cls?
dry out the cls
Preservative free saline is the best option for lens storage overnight. T/F
FALSE
The purpose of therapeutic lens is to help normalize an abnormal appearance of the eye. T/F
FALSE
Therapeutic lenses can help with recurring erosion of the cornea. T/F
TRUE
Silicon rubber lenses are used to treat and correct for keratoconus. T/F
FALSE
What is the purpose of sequestering agents?
remove protein of a contact lens
Dyslexia can be fixed by therapeutic application of a prophylactic tint. T/F
FALSE
SPK is a sign of solution toxicity?
YES
Hydrogen peroxide must be neutralized before the cls is clean and ready for use. T/F
TRUE
What are the 2 methods used for disinfection of a contact lens?
Heat
Chemical (cold)
Which lens wearing modalitys are most likely to cause hypoxia? 3
Extended wear
continous wear
lenses that are slept in
A coloured lens can alter surface chemistry of the lens causing the lens to be more dry. T/F
TRUE
A contact lens can be used to correct vision in patients with nystagmus. T/F
TRUE
What is the name of the tinted lens designed to enhance performance by enhancing contrast for athletes?
Performance enhancing tinted lens (X Chrom)
What is fenstration?
Hole drilled in lens
What agents in solution restricts growth of microorganisms?
preservatives
What is the purpose of a prophylactic lenses?
prevent injury or disease of the eye
What does the viscosity agent in solutions do?
improves the wetting time and comfort of the solution
What type of lens show be used for someone suffering with recurrent corneal erosions?
Bandage lens
What does ‘three point touch’ refer to?
Touch at the corneal apex with lens bearing pressure residing on the peripheral cornea
Acanthamoeba is a preservative found in solutions. T/F
FALSE
What condition can be caused by a steep fitting scleral lens?
Blanching
A contact lens wearer who reacts to preservatives will benefit from using the hydrogen peroxide system. T/F
TRUE
Prosthetic tinted lenses is used to change the eye color for cosmetic purposes or for fun. T/F
FALSE
A nevus can be caused by a toxic reaction to hydrogen peroxide solution. T/F
FALSE
Wearing EW lens can cause the epithelial cells to change. T/F
TRUE
