Exam Flashcards
Essential requirements of handover (6)
- seating of Px, getting Px to look at frames etc before getting a dispenser
- addressing the Px in the correct manner
- introduction of colleagues
- clarification of requirements e.g. any info about budget considerations
- clear communication
- farewell your patient and thank them for their time
When should a frame be adjusted to standard alignment? (4)
- after manufacture of the frame
- after the frames have been on display for some time
- after glazing (unless already adjusted to Pxs face)
- When Px’s frame has been bent out of shape
Process of standard alignment (9)
Check:
- contour of the frame front
- that the lenses are in the same plane
- angles of the temples
- that the temples are in the same plane
- bend of the temples
- conformity on a flat surface
- folding evenness
- joint screws
- overall alignment
Define temple length
distance from where the screw intersects the horizontal axis of the temple to the tip of the temple
Define length to bend
the distance between where the screw intersects the horizontal axis of the temple to the centre of the bend
Define temple width
the distance between the inside of the temples at the base of the fitting triangle
Define pantoscopic tilt
the angle formed by the temples and the frame front when the bottom front edge of the frame is brought towards the cheeks
Define let-back
the angle between the temples and the frame front
Define frontal angle
the angle formed by a line parallel to the rim of the frame where it rests on the nose and the perpendicular line dividing the nose in two viewed from directly in front
Define splay
the angle formed by a line parallel to the rim of the frame where it rests on the nose and the perpendicular line dividing the nose in two, viewed from above
Define crest
the surface at the apex of the bridge which sits on top of the nose
Define crest angle
the angle formed by a line parallel to the inside surface of the apex of the bridge where it rests on the nose and a line running parallel to the front of the face
Define crest height
the distance from the horizontal centre line to the crest of the frame
Why should let-back have an equal angle on both sides?
so that the lenses will sit the same distance from each eye when the frame is fitted
Why should temple fold angles be the same and closely parallel? (2)
- so that the frame can easily fit into a glasses case
2. if the frame has a deep shape the side that doesn’t hang down may rub the inside surface of the lens - scratching it
Why should you burr the dimple end of the screws? (3)
- stop the temples from becoming lose
- stop the screw from falling out
- prevent the frame from falling apart
define effective diameter
distance between the geometric centre of the lens shape and the furthest point on the lens edge multiplied by two
Characteristics of a good kids frame (5)
- larger crest - childs nose is flatter and bridge not properly developed
- larger frontal angle - childs nose is flatter and has less projection at the bridge
- larger splay - flat nose shape and lack of projection
- flatter panto - lack of projection from the face and relative projection of the cheeks
- ability to shorten temples - childs head is much smaller
How do you apply the centre of rotation rule?
- adjust frame to final fitting
- mark up lenses with appropriate measurements
- have Px tilt their head back until pantoscopic tilt is neutralised and lenses are at 90 degrees to the floor
- get Px to look at a target at the same height as their eyes
- Note where the pupils were positioned relative to the markings
- this will drop the optical centre position to the correct fitting height = 1mm for every 2 degrees of pantoscopic tilt