LENS TYPES

Not all lenses are the same—each type is designed to enhance your vision and comfort in different ways.

SINGLE VISION

The entire lens has the same power throughout it, and may correct either Myopia (near-sightedness), Hyperopia (far-sightedness) or Astigmatism. Single Vision lenses correct for a single point of focus whether it be Distance, Intermediate, or Near.

BIFOCAL

This type of multifocal contains 2 different powers in the lens. Standard Bifocals typically come in a Flat Top 28(FT28), Flat Top 35(FT35) or Executive. The 28 and 35 means how wide the bifocal is from side to side and Executive represents that the bifocal goes across the entire lens.

TRIFOCAL

This type of multifocal contains 3 different powers. Typically the top power is for distance, the middle power is for intermediate, and the bottom power is for reading. Trifocals also come in 7 x 28, 8 x 35, and Executive.

PROGRESSIVE

Instead of having just 2 or 3 lens powers like bifocals or trifocals, progressive lenses provide a seamless progression of many lens powers for all viewing distances. Progressive lenses also have more cosmetic appeal due to the invisible zones.  There are no harsh lines, as in bifocals and trifocals.

LENS MATERIALS

Material Index & Abbe Advantages Disadvantages
Plastic Index: 1.498
Abbe: 58 		Almost as clear as Glass
Less Expensive
Tintable		 Breakable
Heavy
Thicker than Poly
Glass Index: 1.52
Abbe: 59 		Highest Abbe Heavy Easily Breakable
Trivex Index: 1.54
Abbe: 54 		Impact Resistant - Tintable
Block 100% of UV - Lightweight
Higher Abbe than Polycarbonate		 Thicker than Poly
Polycarbonate Index: 1.568
Abbe: 30 		Lightweight
Block 100% of UV
Impact Resistant - Best Value		 Lower Abbe
Ultra-Hi-Index Index: 1.74
Abbe: 45 		Thinnest Lens Available
Block 100% UV		 Lower Abbe
More Brittle
Hi-Index Index: 1.67
Abbe: 32 		Thin and Light
Block 100% UV		 Lower Abbe

LENS & FRAMING SIZING