Chapter 4- Dispensing part I (1) Flashcards
What is a dispensing optician?
Person who is qualified to fit and supply glasses and lenses with the prescription from the optometrist.
What can dispensing opticians specialise in?
They can specialise in low vision and contact lenses.
What qualification would a dispensing optician have?
They would have an ABDO qualification- Association of British association dispensing optician
What types of lenses are there?
1- Single vision
2- Bifocal
3- Trifocal
What are single vision lenses?
They are lenses for one distance only
What can the Rx be for single vision glasses/lenses?
Spherical, cylindrical, or both.
What does DV, IV, and NV stand for?
DV = Distance vision IV = Intermediate vision NV = Near vision
What is an Rx?
Rx = prescription
For the prescription, what does DV equal?
DV = DV Rx
For the prescription, what does IV equal?
IV = DV Rx + IV add
For the prescription, what does NV equal?
NV = DV Rx + NV add
What are bifocals?
They are glasses/ lenses designed for two distances.
DV and NV, DV and IV, etc.
Bifocals have a near portion. What does it do?
Assists with near vision
What is the disadvantage of bifocals?
It is not cosmetically appealing.
What are trifocals?
Glasses for all three distances.
What are varifocals/ progressive power lenses?
A lens that allows a number of focusing distances for dv, iv, nv, etc.
What do the majority of varifocal lenses have over most of the upper hemisphere?
They have a stabilised zone of distance vision
What do varifocal lenses have at the lower edge of the lens?
A small stabilised zone for near vision.
What connects the lower edge and the upper hemisphere?
A narrow channel with a gradually increasing plus power called the progression zone.
What are the disadvantages of bifocals and varifocals when using computers?
1- Stiff neck when moving your head up and down to look through the right lens.
2- Visual discomfort (asthenopia)
What are visual display terminals?
Computer, etc
When seeing patients, you would ask them whether they use a computer (visual display terminal) and you ask:
1- How many hours a day they use it
2- How many days a week they use it
3- What is their viewing distance
What can happen to your eyes when using a computer?
You can get sore and dry eyes
Why do you get sore and dry eyes when using a computer?
Because when you concentrate on the computer, the blink rate is reduced.
If a patient complains about having sore eyes, you would:
1- Tell them to take regular breaks when sat at the computer
2- If it is too bright, you would pull the blinds down or turn the brightness down on the computer to reduce it
3- To have screens below eye level
4- To have screen 90 degrees to the window to prevent any glare coming onto the screen
