Sunglasses

Who wears photochromic lenses? Photochromics are versatile enough to suit almost every occasion. For golf or tennis players, where good vision is as important as comfort and protection, or schoolteachers supervising playground or sports activities as well as spending time in the classroom, photochromic lenses are ideal.

For enhanced performance your optician will tell you whether your photochromic lenses can be treated with hard coating, anti-glare and/or water repellent treatments. When combined, all three treatments make them ideal for sports and prevents misting when coming from outdoors to indoors. Driving in photochromic lenses Whilst driving, your photochromic lenses may not become as dark as they do outside. This is nothing to worry about, whether the lenses are activated or not your eyes are still being fully protected by the windscreen, which blocks out the harmful ultraviolet light that would normally make the photochromic lenses darken.

What about extreme conditions of sunlight? People exposed to intense periods of extreme heat and high levels of UV should consider a second pair of prescription sunglasses made to the British Standard 2724. But in most day to day situations and activities, photochromic lenses are the most versatile option for prescription wearers. Tips for handling and taking care of your frames and lenses Follow the advice of your optometrist or dispensing optician about how to look after your photochromic lenses. Here are some basic guidelines: Keep your lenses and frames clean. To clean lenses, your practitioner will advise you whether you should dip them into warm, soapy water and rinse them under running water, or use a spray and special microfibre cloth suitable for plastic lenses. Use two hands to remove your spectacles, using even pressure on both side pieces. Keep your glasses in a case. Open the case fully and gently pull them out (sliding them in and out may dull the lenses).

Although there is no reliable evidence to suggest that even long-term intensive use of VDUs is damaging to the eyes, it is true that VDU users tend to complain of eye strain more than non-users. This is likely to be due to fatigue through causes such as: - Insufficient and infrequent rest periods - Incorrect positioning of the screen and/or documents - Unsuitable lighting - Poorly designed work area - An uncorrected eyesight fault such as long sight, short sight, astigmatism or presbyopia - The eyes not working 'as a team' Any of these conditions could lead to fatigue; all can be overcome through good design of the working environment and by regular eyecare. Take frequent breaks When you work at a VDU your eyes can be focused on the screen for long periods so it is important to take a brief rest and give your eyes a break every 20 minutes or so.

You should have sufficient space behind the screen for you to be able to look beyond it and relax your eyes. Screen settings and position You should adjust your VDU to levels of brightness and contrast that you find comfortable. Keep the screen clean and free of dust and fingermarks. If possible, position it so that windows or other light sources are to the side rather than in front or behind it - if you can see a window or light unit reflected in the screen, move the VDU until the reflections disappear, or adjust blinds or curtains. The surface of the screen should be between 33 and 100cm from your eyes and if you are working from copy documents these should be placed at roughly the same distance to avoid continual re-focusing. Lighting Try to eliminate as much glare as possible from the region around your screen. This is not always straightforward, but as a general rule: - The office lighting should be set at a level which allows the documents and screen to be read easily.

Additional lighting - such as an Anglepoise lamp - may sometimes be necessary to achieve this. - Avoid an uncurtained window directly in front of or behind your working position - Any window reflected in the screen should be fitted with blinds or curtains - Walls and desk surfaces should be non-reflective and neutral in colour - Your legal entitlement as a VDU user Since 1993 EC legislation has placed responsibilities on employers whose employees regularly use VDUs as part of their work. These regulations are also designed to protect users who may work for an employer from home, or any other location which is not the employer's main office. If you are classified as a user, your employer must: - Provide a full eye examination free of charge to you when you commence VDU work and at regular intervals thereafter - Provide a full eye examination free of charge to you if you are experiencing visual problems which may be due to working with a VDU - Pay for a pair of basic glasses if it is shown that you require these specifically for VDU use, or an equivalent amount of money towards a pair of your choice - Provide adequate breaks or changes of activity to reduce general visual fatigue - Provide health and safety training information relating to the workstation.

Keep you informed about the Regulations, particularly those relating to eyesight, rest breaks and guidance on work station minimum requirements. Spectacles Only a small proportion of users will need spectacles specifically for working at a VDU and the majority of these will be what is known as presbyopic. Presbyopia affects us all as we get older. Around the age of 45 people begin to find they lose the ability to focus on objects that are close up. Spectacles with single vision, bifocal or varifocal lenses can all be used successfully for VDU work. Contact lenses are also suitable, but wearers should try to blink regularly which keeps the lenses comfortable.

When you concentrate on the screen for long periods, your normal blinking rate slows down. Presbyopic contact lens wearers may need additional reading glasses. Reflection-free lenses Reflection-free lenses are well worth considering for VDU users. Because they eliminate almost all reflections VDU glare is considerably reduced, providing clearer and sharper vision. The eye examination If, as a VDU user, you are entitled to a free eye examination, make a note of the following points that will help your eyecare practitioner assess the effect that VDU work may be having on your sight: - The date of your last eye examination - How long you have worked with VDUs - The number of hours per day that you work at a VDU - The distance from your eyes to the screen, keyboard and any documents you refer to while working - The position of the screen (eg. above or below eye level, to the left or right of your sitting position) - The size of the screen you use, its resolution and refresh rates (if known) - Any symptoms associated with VDU work

Photochromic lenses are available in glass and plastic. Historically, glass offered the best photochromic eye protection with a faster reaction and darker tint when activated. Recent innovations and some of the newer products available have shown that plastic's performance has caught up and is now very versatile. Glass photochromic lenses are often twice as heavy as plastic. They are not uniform in tint (which affects the colour of the lens when activated by sunlight) and are not shatter resistant. Plastic photochromic lenses, on the other hand, are both shatter and scratch resistant. Ask your optometrist or dispensing optician about the latest product and tint range for you particular prescription. Does the colour of the lens make a difference? Traditionally, grey is the most popular colour in photochromic lenses, but tints can vary. Recent research shows that a brown tint is largely preferred in Europe and is widely available in most practices.