1. SPECTACLE LENSES (JEDI)

ROGER BACON

ROGER BACON

Earliest recorded comment on the use of lenses for optical purposes

SALVANI D’ ARMATE

in 1284, he is believed to have created the first wearable eyeglasses.

• Better Optics

• Scratch resistant

• Heat resistant

• Heavier

(4) Glass lenses advantages

• Lightweight

• Easily tinted

• Impact Resistance/ more durable

• Standard Choice

• More affordable

(5) (CR-39) advantages

• Bifocal

• Trifocal

• Multifocal

(3) Types of multifocal lenses

SINGLE VISION LENS

SINGLE VISION LENS

SINGLE VISION LENS

These lenses have a single prescription power throughout the entire lens.

SINGLE VISION LENS

They are commonly used for myopia or hyperopia.

Bifocal

combine two prescriptions in one lens.

distance vision, near vision

The upper part corrects ________, while the lower part has an additional segment for ___________(usually for reading)

Jack n’ the box

Usually accompanied or susceptible to the ________ phenomenon

Executive (Benjamin Franklin):

The entire bottom half of the lens is dedicated to near vision correction.

Executive bifocals

Named after Benjamin Franklin, who invented the first bifocals.

Executive (Benjamin Franklin) or Executive bifocals

Very noticeable “jack n’ the box” phenomenon

Also called a half-moon lens design

Still exhibits the "jack-in-the-box"

Kryptok Bifocal

The optical centers for distance and near vision are far apart from each other

Half moon bifocals

Also known as flat-top, straight-top, or D segment bifocals.

Half moon bifocals

The optical centers in this lens design are not as widely separated compared to the Kryptok bifocal lenses.

Ribbon Segment

consists of a narrow rectangular area at the bottom of the lens.

Ribbon Segment

are less common but offer versatility.

Round Segment

These bifocals have a rounded segment at the bottom for near vision correction.

Round Segment

The transition between the two segments is visible

Round Segment

are another option for managing presbyopia.

In addition to distance and near vision, they include an intermediate segment for computer use or other mid-range tasks.

TRIFOCAL LENS

Generally, for experimentation, not present in the market

PROGRESSIVE LENS

have a gradual transition between the different prescription zones.

PROGRESSIVE LENS

Eliminating the “Jack n’ the box phenomenon”

PROGRESSIVE LENS

Distorted area on the sides should not be used.

PROGRESSIVE LENS

Newer and more expensive types have smaller distortion and wider viewing area

Polycarbonate Lenses

are impact-resistant and thinner

Polycarbonate Lenses

commonly used for children, sports, and safety glasses.

Polycarbonate Lenses

provide built-in ultraviolet protection.

Trivex Lenses

similar to polycarbonate but offers higher quality optics.

Trivex Lenses

provides clearer vision and is a good choice for those seeking improved visual clarity.

High index Lenses

Made up of a special plastic material that refracts light differently than regular plastic lenses.

High index Lenses

They correct vision with less material, resulting in thinner and lighter lenses.

High index Lenses

Ideal for high prescriptions, they offer better cosmesis and comfort.