SINGLE VISION

Single vision lenses have the same focal power throughout (top to bottom) and can be used to correct nearsightedness, farsightedness, astigmatism, or a combination of these disorders.

Most people who wear glasses before the age of 40 have single vision lenses.

BIFOCAL LENSES

Some time after age 40, you will begin to notice the symptoms of presbyopia, including that feeling that your arms ‘aren’t long enough’ to hold a newspaper or magazine at a position where you can read it clearly.

People with presbyopia generally need lenses for reading and may need a different lens for seeing in the distance. While most presbyopes these days choose varifocal lenses, there are instances where conventional bifocals and trifocals can be more suitable.

Bifocal lenses have two parts – the upper part normally used for distance vision and the lower part used for near vision tasks such as reading.

TRIFOCAL LENSES

Trifocal lenses have three different focus areas – the top for distance vision, the centre for intermediate vision, and the bottom for near vision.

The intermediate segment is used to view objects at arm’s length - computers are an excellent example of something that is in a person’s intermediate zone, as are the gauges on a car’s dashboard.

LENSES FOR SPECIALISED USE

COMPUTER LENSES are designed so the monitor and papers next to it are in focus when the head is held in a natural position.

DOUBLE D TRIFOCALS are sometimes prescribed for people who need close vision overhead.

These lenses have a reading area at both the top and the bottom of the lens
and are often helpful to pilots, electricians and others who need clear near
vision when looking up as well as down.

VARIFOCAL LENSES

No-one likes to advertise their age – especially 40-something adults who start having trouble reading fine print. Varifocal lenses give you a more youthful appearance by eliminating the visible lines found in bifocal (and trifocal) lenses.

Varifocal lenses provide the nearest thing to natural vision as they provide a smooth, seamless progression through the lens powers, giving you clear vision in the distance, up close and all distances in between. Holding your head in a comfortable position, you can simply look straight ahead to see in the distance, move your eyes slightly downward to view your computer through the intermediate zone and lower your gaze a bit farther to read comfortably up close.

THERE ARE MANY CHOICES NOW AMONG THE VARIOUS STYLES OF VARIFOCAL LENSES AND WE ARE PROUD TO PROVIDE THE MOST EXTENSIVE RANGE OF VARIFOCAL LENSES FROM ALL THE LEADING LENS MANUFACTURERS SUCH AS ESSILOR, HOYA, NIKON, RODENSTOCK AND ZEISS, TO NAME BUT A FEW.

Our enormous range of varifocal lenses allows us to provide you with lenses to suit all frames and lifestyles. With the new designs in progressive lenses, whether you want a small or a large frame, we have lenses to suit every style of frame. Some varifocal lenses are made especially for computer use and have a wide intermediate zone, whilst others have a larger reading portion. We will discuss with you which type of lenses will work best for you and your lifestyle.

OUR EXCLUSIVE CRYSTAL FREEFORM VARIFOCAL LENSES OFFER UP TO A 30% LARGER
VIEWING AREA THAN TRADITIONAL VARIFOCALS AND UP TO 40% LESS EDGE DISTORTION.

GET THE BIGGER PICTURE WITH CRYSTAL FREEFORM PROGRESSIVE LENSES! We are proud to be amongst the first to bring you the latest technology with our new  Crystal Freeform progressive lenses. Crystal Freeform progressive lenses offer up to a 30% larger viewing area than traditional progressives and up to 40% less edge distortion.

Crystal lenses are suitable for many sizes of frames and are available as high-index, Polarised and Transitions. With our unique offer you could have two pairs of genuine Crystal Freeform progressive lenses. CRYSTAL FREEFORM PROGRESSIVE LENSES ARE ONLY AVAILABLE AT CROWN OPTICAL AND DIREKT OPTIK

THINNER LIGHTER LENSES

If you would like your lenses to be thinner and lighter, then you should choose high-index lenses. High-index lenses are made of a special material that refracts light in a different way than regular lenses. With high-index lenses, vision can be corrected with less material, making the lens much thinner.

Nearly everyone can benefit from thinner, lighter lenses. High-index lenses can be up to 50% thinner than regular glass or plastic lenses and they're usually much lighter too.

Though these lenses are especially beneficial if you have a strong prescription, they can make a noticeable difference in the appearance of virtually any pair of glasses.

Various high-index lenses are available today in different price points based on how much thinner they are compared to regular plastic lenses.

The lenses are classified by their 'index of refraction' (or 'refractive index').

Generally, lenses with a higher index of refraction will be thinner (and usually more expensive) than lenses with a lower index.
The refractive index of regular plastic lenses is 1.50. The refractive index of mid to high-index plastic lenses ranges from 1.53
to 1.74.  Those in the range of 1.53 to 1.59 are about 20% thinner than regular plastic lenses, whereas 1.74 high-index lenses
are about half the thickness of regular plastic lenses.

Most popular lens designs (single vision, bifocal, varifocal and photochromic) come in high-index materials and we will advise
you which lens is available in your prescription.

Note: As high-index lenses reflect more light than regular plastic or glass lenses, an anti-reflective (AR) treatment is highly recommended for these lenses.

ASPHERIC LENSES

To make high-index lenses even more attractive, most of them have an ‘aspheric’ design. This means that instead of having a round (or ‘spherical’) curve on the front surface, these lenses have a curve that gradually changes from the centre of the lens to the periphery. This makes aspheric lenses noticeably flatter for a slimmer, more attractive lens profile.

Though aspheric lenses offer advantages for all prescriptions, they are particularly beneficial if you are farsighted. Aspheric lenses greatly reduce the magnified ‘big-eye’ look caused by regular, highly curved lenses for farsightedness, and they greatly reduce the ‘bulge’ of the lenses from the frame. What is more, because they have a slim profile, aspheric lenses are much lighter and provide superior peripheral vision compared to conventional lenses.

Note: As aspheric lenses have flatter curves than regular lenses, this may
cause more noticeable reflections. Therefore an anti-reflective (AR) treatment
is recommended for these lenses.

PHOTOCHROMIC LENSES

Photochromic lenses automatically darken to a sunglass shade outside when exposed to sunlight and then quickly return to a clear state indoors. These lenses also provide 100% protection from the sun’s UV rays and are available in a wide variety of lens materials and designs, including bifocal and varifocal lenses.

The amount of darkening that most photochromic lenses undergo depends on how much UV radiation they are exposed to. As a general rule, these lenses won’t get as dark behind the windscreen of your car because the windscreen blocks out much of the sun’s UV rays that cause the lenses to change colour.

POLARISED LENSES

When light hits a reflective surface, such as water, sand, snow, even cars and buildings, the light can become polarised, resulting in glare that can interfere with your vision. Only polarised lenses can remove this glare.

We've all experienced glare in our daily environment ......perhaps spending the day at the beach or on a boat with the sun illuminating the surface of the water, or driving in a car with the sun reflecting off the dashboard or road.

Ordinary tinted sunglass lenses cannot block glare – only polarised lenses can give you comfortable vision by blocking out this dangerous, blinding glare.

When we spend time outdoors, glare and reflections are literally all around us. When we put on a pair of polarised lenses, our vision is improved beyond just removing dangerous blinding glare. Colour and depth perception is improved, along with clarity and contrast of objects.

Photographers have known this secret for years and often use polarising filters to achieve bolder colours and deeper contrast in their photographs (in addition to removing glare, of course). Depending on the colour you choose for your polarised lenses, colour and depth perception may be enhanced even more.

PHOTOCHROMIC POLARISED LENSES

Relaxed and comfortable vision is extremely important while driving a car. Research has shown that simply protecting the eyes from the sun is insufficient for glasses wearers during driving. Rapidly changing light conditions, continuous exposure to blinding glare and the endless sequence of visual distractions require lenses which understand the situations drivers encounter and adjust accordingly. Drivewear lenses have been developed based on this concept – truly intelligent lenses for drivers.

DRIVEWEAR LENSES:

• Effectively block blinding glare in any weather
• Intelligently and quickly adapt in the car and outside (darken or fade) depending on the available light
• Enhance colour contrast
• Guarantee that traffic signal recognition is not impaired in any weather conditions
• Improve clarity of vision and depth perception
• Eliminate necessity of changing glasses every time light conditions change
• Dramatically improve driver’s safety