Robsons Opticians offer an extensive range of prescription sunwear. Options include Polarised prescription lenses and Photochromic lenses.
How are Polarised Lenses effective in blocking glare?
Light waves travel in all direction, some travelling in vertical waves and some in horizontal waves. When light hits a reflective surface eg water, a wet road or car bonnet, some of the light becomes polarised; some of the vertical light waves are absorbed at the surface, and horizontal rays bounce off the surface creating glare.
Polarised lenses contain millions of microscopic iodine crystals which, act in a manner not dissimilar to venetian blinds; the horizontal rows of iodine crystals block out horizontal polarised light waves, letting only (non-polarised) vertical light waves reach the eye.
This results in comfortable vision with no glare.
In addition to blocking blinding glare, polarised lenses can also enhance vision by improving contrast, and improving contrast, colour and depth perception.
Are Polarised lenses available in my lens power?
Polarised lenses are available without prescription, or in single vision, bifocal or varifocal lens forms, and can be fitted to any of our wide selection of frames. They are supplied in standard index or thinner lens forms, and in a choice of grey or brown.
We would be pleased to demonstrate the effect of polarised lenses if you call in to the practice.
How are Photochromic lenses effective as sunspecs?
Photochromic lenses darken when exposed to sunlight. From a very pale residual lens colour – almost as clear as an ordinary lens – the photochromic element within the lens reacts to sunlight causing the lens to darken and reducing the amount of light reaching the eye.
Photochromic lenses are available in both glass and plastics, and in a huge range of lens types; single vision, bifocal, varifocal, standard thickness, thinner forms and Individual Lens designs.
Technological development relating to plastics photochromic lenses is ongoing, with the most recent lens material being Transitions VI which changes faster and through a wider transmission range than previous types.
Transitions VI lenses block 100% of the sun’s harmful UVA and UVB rays, and are available in grey or brown