Lenses

Lens Styles
From your eyeglass prescription, we are able to determine which style of lens is appropriate for you:

Single Vision	Single vision lenses are just that—they correct a single, particular vision such as distance if you're nearsighted (a condition called myopia) or close up if you're farsighted (a condition called hyperiopia).
Bifocal	Bifocal lenses are used to correct for both distance and near. The bifocal lens will typically have a horizontal line or a D-shaped segment in the lower portion of the lens which brings near work into focus.
Trifocal	Trifocal lenses, like bifocal lenses, will have visible lines across the lens, either in a D-shaped segment or across the entire lens. The top of the lens is for distance, the middle segment is for arm's length tasks, and the bottom segment is for close-up work.
Progressive Addition Lenses (PALs)	Progressive Addition Lenses (PALs) are cosmetically more desirable for most individuals, as there are no visible lines. Instead of having "steps" in the prescription like a bifocal or a trifocal, the change in prescription acts like a "ramp" for a smooth transition from distance, to intermediate, to near viewing.

Demonstrator units are available in our office to show you the differences between
the lens styles and to help you decide which one is right for you.

Lens Materials

Material	Optical Quality	Weight & Thickness	Scratch Resistance	Impact Resistance
Glass	Excellent	Heaviest & Thickness	Superior	Poor
Plastic (CR39)	Excellent	Mid-Range (approximately 1/3 lighter and thinner than glass lenses)	Good (Can be coated to increase scratch resistance)	Good
Hi-Index Plastic	Very Good	Lighter and thinner than plastic or glass	Good (Can be coated to increase scratch resistance)	Good
Polycarbonate	Good Some wearers may notice faint halos around images against a white background.	Lightest and thinnest lens material available. Polycarbonate lenses are approximately 1/2 the weight of plastic lenses.	Fair Polycarbonate lenses are factory-coated, but care must be taken to avoid scratches.	Superior We recommend polycarbonate for anyone active in sports or in work environments where eye protection is necessary.

Lens Treatments

Scratch-resistant coating	These coatings are applied to plastic and polycarbonate lens materials to increase their resistance to scratches and prolong their usable life. Some scratch-resistant coatings are available with a lens replacement warranty.
Antireflection coating (AR coating) Crizal ™	Antireflection coating This lens treatment reduces glare from light sources. It is especially helpful for those bothered by glare from oncoming headlights when driving at night and for those who work with computers and are bothered by screen glare. Additionally antireflection gives the cosmetic advantage of virtually eliminating the glare that others see from your eyeglasses.
Photochromic Lenses	Photochromic LensesThese lenses change color from clear or nearly colorless to gray, brown or green when exposed to an ultraviolet light. Photochromic lenses are available in all lens materials, although certain lens styles (e.g. Franklin bifocal) are not available in all materials.
Ultraviolet Coating (UV Block)	This coating , when applied to glass or plastic lenses blocks the transmission of ultraviolet light to the eye. It is thought that ultraviolet light exposure is a factor in the development of cataracts. Polycarbonate lenses already have ultraviolet blocking properties and do not require an additional coating.

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Dr Burley & Associates/Affordable Advanced Hearing Instruments
5012 Liberty Avenue
Vermilion, Ohio 44089
(440)967-3937

Family Hearing and Vision Care
8 South Main Street
New London, Ohio 44851
(419)929-2461

"You should have your eyes examined!"