NBEO Contact Lenses

Does a larger diameter of CL mean a steeper or flatter base curve?

Larger diameter = flatter curve

Does a higher diopter base curve for CL mean a steeper or flatter curve?

Steeper curve= higher diopter

If you make the base curve steeper, what do you need to do to the CL Rx?

Add Minus (SAM/FAP)

If you make the base curve flatter, what do you need to add to the CL Rx?

Add Plus (SAM/FAP)

What are the average corneal K values?

42-45 Diopters for the average cornea.

What is the difference between sphere power effect (SPE) bitoric CL and cylinder power effect (CPE) bitoric CL?

SPE bitoric contact lenses correct primarily for spherical power, while CPE bitoric lenses are designed to correct for astigmatism by managing cylindrical power.

SPE = no unwanted cyl if it rotates. CPE = can have unwanted cylinder if it rotates.

SPE = difference between two BC = difference between two lens powers

CPE = power difference and base curve difference not equal

What is a radiuscope used for

Measuring BC of RGP CL

What is a V-channel gauge used for?

Measuring overall diameter of CL

What is most commonly used to evaluate the edge profile of an RGP CL?

Shadowscope

How much clearance over the steepest area of the cornea is considered ideal for a scleral CL?

100-300 microns

NCT over soft CL does not affect results unless the power of the lens is greater than _____ or less than ______. Is it over-estimated or underestimated with each?

• +3.00 and up causes a falsely elevated IOP

• -6.00 and lower causes a falsely depressed IOP