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Acetate is a nylon-based plastic. Compared to standard plastic, it is more durable and retains its shape and colour for longer.

Base Curve

The base curve of a lens relates to the amount of curvature of the front of the lens. The higher the base curve, the greater the curvature of the lens.


A di-electric material is poor at conducting electricity. Safety glasses labelled as di-electric contain no metal parts.

Digital Inner Surface Technology

An innovative method of manufacturing RX safety eyewear lenses resulting in optically-ideal base curve across all viewing zones.


Waves of light are made of travelling energy composed of electric and magnetic fields. Light waves form just part of the wave spectrum.

Polycarbonate Lenses

Polycarbonate lenses are the standard type of lens used in safety glasses. They are up to ten times more impact resistant than plastic lenses whilst also being thinner and lighter. In its original state, polycarbonate is a thermoplastic which is then formed into a shape using injection moulding before cooling.


Revo is a type of lens coating offering an intense coloured and mirrored effect.


Originating from an abbreviation of the latin verb 'recipe', RX means prescription.


A coating applied to many models in the Riley spectacle range. The TECTON™ coating makes the lenses to which it is applied more resistant to abrasion and fogging. This equates to the markings 'K' and'N' as part of Standard EN 166.


Lenses coated with the TECTON 400 coating will eliminate harmful UV rays from passing through the eyewear from the sun. This high performance coating also contains the antifogging, anti-scratch and moisture repellent properties of TECTON which is applied to both sides of the lens.


TPE is an acronym for Thermoplastic Elastomer. TPE material is a flexible material that is very pliable and is often a evolutionary replacement for traditional rubbers.


A plastic polymer used to make eyeglass lenses. The abbreviation is short for 'Columbia Resin 39' which was the 39th formula of a thermosetting plastic developed by the Columbia Resins project in 1940. CR-39 is a registered trademark of PPG Induistries Ohio, Inc.

UV Light

Ultraviolet (UV) radiation is part of the electromagnetic spectrum that reaches the earth from the sun.

It is invisible to the naked eye and is comprised of wavelengths classified as UVA and UVB. UVA and UVB light can both contribute to eye damage and cancers.


UVA rays account for up to 95 percent of the UV radiation reaching the Earth's surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent. They are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass. UVA rays can pass through the cornea and reach the lens and retina inside the eye.

Overexposure to UVA radiation has been linked to the development of certain types of cataracts, and research suggests UVA rays may play a role in development of macular degeneration.


UVB light's intensity varies by season, location and time of day. UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces such as snow or ice. UVB rays are thought to help cause pingueculae and pterygia. These growths on the eye's surface can become unsightly and cause corneal problems as well as distorted vision. In high short-term doses, UVB rays also can cause photokeratitis, a painful inflammation of the cornea.

Visible Light Transmission

Visible light transmission is the amount of light that can pass through a lens.


The size of light waves is measured in wavelengths. The wavelength is calculated by determining the distance between corresponding points on consecutive waves. This can be measured from peak to peak or from trough to trough. The human eye can only see wavelengths of 400 to 700 billionths of a metre (nanometres). This is commonly called the visible spectrum.