Which spectacle lenses

Like all contact lenses, they carry a risk of dry eyes, injury, infection and vision loss. Toric soft contact lenses may correct astigmatism but are not as efficient as RGP lenses. These are also more expensive than other contact lenses. Bifocal or multifocal contact lenses are available in both soft and RPG varieties.

They can correct nearsightedness, farsightedness, and astigmatism in combination with presbyopia. Like bifocal glasses, these lenses mean that the patient does not need to have a pair of glasses for reading.

In case you do not want the hassle of spectacles or problems related to contact lenses , you can always discuss the various options available for surgeries for removal of glasses with your treating eye doctor. We are fully functional now! Spectacles So you have been told you need to wear glasses?

General guidelines for choosing a frame best suited to your face are enumerated below. Lens material Refractive index Salient features of the lens High index plastic 1. Block percent UV. High index plastic 1. Lightweight, less expensive and thinner than 1. Significantly more impact-resistant than CR plastic and high-index plastic lenses except polycarbonate and Trivex Polycarbonate 1.

Light-weight Impact resistant CR 39 1. Shape of face. Shape of frame. Ask the dispensing optician to talk to you about better lens materials and designs. If you are very long-sighted, your spectacle lenses can feel thick and heavy and magnify your eyes. Aspheric lens designs can thin and flatten the lens, reducing the magnifying effect. Some people with very high spectacle prescriptions benefit from lenticular lenses. The part of the lens that helps you to see better is in the centre, within a wider border of clear lens, giving a shape like a fried egg.

This cuts the central thickness of the lens and ensures the specs are lighter. A slab-off lens can help if you have a difference between your two eyes, and also need different powers of spectacle lens for distance and near vision.

This can lead to an imbalance between the two eyes when you try to read. The slab-off technique can be applied to bifocal and varifocal lenses. By altering the angle at which one lens is ground you can avoid the lenses inducing double vision. Franklin split lenses are special bifocals which provide a very wide zone for near vision.

They are produced by cementing together two lens halves, one the distance portion and one the near portion. They can help people who have a difference between their two eyes to avoid vertical jump or imbalance. Freeform lenses use computer-aided design and surfacing to create high-level, customised spectacle lenses with your unique prescription.

They can help to reduce glare and halo effects caused by light sources at night, such as car headlights. To create freeform lenses, once you have chosen a frame, the Registered Dispensing Optician will fit the frame to your face. They will then scan your eyes using specialized equipment that measures your face and eye position. They will also measure how the frame sits in front of your eyes, how it wraps around your face, and even how you tilt your head.

The software combines your physical data with your spectacle prescription in order to provide the best vision, day and night. The optician will send your order direct to an optical lab. Your lenses will be created on a computer-driven, free-form generator. This machine is able to work to extremely high levels of accuracy and can generate more complex surface shapes than traditional glazing equipment.

The lenses are then fitted to your frame. Finally, the Registered Dispensing Optician will readjust the frame for the best fit on your face. Freeform lenses use an advanced manufacturing technique which reduces aberrations in spectacle lenses.

You may not notice spectacle lens aberrations, or if you have a high prescription and high index lenses you may have noticed a coloured tint to the periphery of what you can see when you are looking away from the centre of your lens. Advances in lens manufacturing mean that lenses can be made without these aberrations. If you want sharper vision, or suffer from glare and problems with night vision, talk to a Registered Dispensing Optician about freeform lenses.

Anyone can benefit from freeform lenses, but you will find most benefit if you have a high prescription, if you are bothered by glare or your vision seems indistinct. Make sure that you have had a recent eye examination, then talk to a Registered Dispensing Optician about freeform lenses. These are excellent choices for people who use both distance and reading glasses, so they do not need to carry around two pairs of glasses wherever they go.

Coating can give your lenses different attributes, making them behave differently according to their environment. Some change colors based upon the lighting, while others offer protection from scratches or the sun. Anti-scratch coating defends your lenses against scratches and abrasions from everyday wear and tear, and helps reinforce them against drops.

Anti-reflective, or AR, coating is another beneficial coating for any pair of eyeglasses. This coating gets rid of annoying glare, halos around lights and reflections on your lenses caused by computers and lights.

They also make your lenses nearly invisible by removing reflections, making your lenses less of an obstruction during face-to-face conversations or photography sessions. Anti-reflective coating is especially important for people with high-index lenses, as these lenses have higher refractive indexes.

This increased refractive index means these lenses will tend to reflect up to 50 percent more light than traditional lenses, causing more glare unless they are equipped with AR coating.

Anti-reflective lenses are important for nearly everyone in the modern world — especially those working around computers or cameras or regularly driving at night. This coating will change the tint of your lenses depending on the amount of light they are exposed to, becoming dark outdoors and clearer indoors. This option does not apply to sun wear options, but is available for nearly all lens materials and designs.

Anyone working in positions where they switch from indoor to outdoor environments frequently will benefit from light-adjusting coating, as well as people who are concerned about their overall eye protection from the sun. Light- adjusting glasses offer the same amount of protection as sunglasses, without requiring you to purchase and carry around an extra set of eyewear. Looking for extra clarity with a pair of yellow-tinted lenses and want to see the world through rose-colored glasses?

We have those options for you! Many people choose to add a hint of color to their lenses to help them see better, or to add a certain look to their eyewear. We offer four colors and four intensities for you to choose from, giving you plenty of customization options. Our color tints cannot be added to polarized or photochromic lenses. These lenses are ideal for people looking to add some more color to their world, as well as their overall look.

Gradient-tint lens coatings are excellent choices for sun wear. These lenses have a dark tint at the top of the lens and then progressively lighten toward the bottom. The resulting lens gives the wearer plenty of sun protection, as well as privacy, but offers you varying degrees of light. Gradient tints are only applicable to lenses for frames above 36mm in height. If you are looking for sun protection, but are uncomfortable with uniformly dark sunglasses, consider gradient tint coatings instead.

This coating reduces the annoying, and sometimes dangerous, reflections on your lenses created by water, roads and other surfaces. These reflections can be distracting or obtrusive, posing a danger to you and your well-being if you are traveling.

If you drive or bike frequently, and travel along bodies of water or slick roads, you could greatly benefit from polarized coating. The simplest form of spectacle or contact lens is the single vision lens, be it concave or convex.

This means that the lens is made to a single prescription to correct a particular vision deficiency, be it short or long-sightedness. A convex lens has either one or both of its surfaces curving outwards, that is, wider divergence from the plan at the centre.

Theses lenses are used to correct long-sightedness hypermetropia. The more long sighted a person is, the more convex the lens has to be to correct the vision deficiency by bringing the rays of light into focus.

A long sighted person's focus is actually some way behind the back of the eye and the convex lens pulls the rays of light together sooner than they normally would be. A concave lens is the opposite of a convex lens.

Here one or both of the lenses surfaces are curved inwards. That is, the centre of the lens is closer to the plane than the edge. A concave lens is used to correct short-sightedness myopia.