Summary
Summary SOFT CONTACT LENSES
- Module
- Optometry (B510)
- Institution
- Glasgow Caledonian University (GCU)
Complete notes on RGP lenses
[Show more]
Seller
Follow
Content preview
667Contact Lens Study notes (B)RGP Lens Types
Corneal diameter lenses (7-12mm)
Corneal – scleral (12.1 – 15mm)
Mini – scleral (15.1 – 18mm)
Scleral (>18mm)
Corneal RGP Fitting
Often regarded as more complex
Fitting= straightforward
Less margin for error if your preliminary measurements though as
require precise fitting
Advantages Disadvantages
Robust- Can be re-polished Physical comfort – need to build up
tolerance
Easy to clean – soaking solutions Greater movement of the lens-
stronger dislodging
Fewer Solution problems
Last longer FB entrapment
Easy to handle (no inside out, rigid)
Stable vision – avoid fit of toric
potential (tear lens)
Good O2 supply
Less dehydration
Customisation (high rx, tints etc etc)
Good tear Exchange
When to choose RGP
Moderate Corneal Astigmatism- avoid the wear of toric lens
High complex rx
History of allergies
Problems with soft contact lens (damage, deposits, solutions, SCL
induced papillary conjunctivitis)
, Financial reasons
Poor compliance with other lenses
High visual demands
When to avoid an RGP
Contact sports
Water sports
Dusty environments – increase in foreign bodies
*Main ones to focus on – BOZR, BOZD, TD*
The BOZD 1-1.5mm smaller than the total diameter (TD). Large enough
to cover pupil in different light conditions
FOZD 0.5mm larger than BOZD
Centre thickness- too thing a lens leads to flexure which can lead to a
breakage and residual astigmatism
Edge lift; to prevent mechanical pressure on the cornea allow tear
exchange and enable lens removal
, Tear Lens
Once picked a lens and looked at fit we are now looking at the rx
When an RGP fits, a small lens is formed between the RGP and the
cornea which is called the Tear lens.
Both combined give the total rx
If lens is flat = negative tear lens
If lens is steep = Positive tear lens
SPECIFICATION = BOZR / TD / BVP (same as soft CL)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller shoaib991. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £10.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78252 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now