BARRY HEWITT - SPECTACLE MAKER - DISPENSER AND MECHANIC
CARING FOR YOUR NEW SPEX
Cleaning your Spex is easy and needn’t be expensive however some lenses require extra care. Immerse glasses in a bowl of clean, cold water with a drop of dishwashing liquid added. Wipe with a soft cloth and dabbing motion to dry. Do not rub vigourously or use tissues as they contain wood fibres. Standard lens cleaner is another option except for polycarbonate lenses as it may contain alcohol or acetone and damage the lens. Ensure glasses are not subjected to extreme temperatures or left on dashboard of car as discolouration may occur.
CHOOSING YOUR CORRECT FRAME SIZE
Most frames have a good degree of size flexibility. The important sizing to check is the glasses frame width and the bridge. A mistake many people make is choosing glasses far too small for the face. An ill-fitting pair of glasses can displace the prescription’s optical centre which could affect vision and make the frames uncomfortable to wear and not visually attractive.
Frame width is the front view horizontal measurement of the frame from one end to the other. For best fit the frame width is measured from temple to temple just above your eyelids. This measurement usually correlates (within a few mm) of the temple or arm of the glasses and is a good indicator of your frame size. OR measure the frame width of a pair of glasses at home that you are happy with.
As there is quite a degree of flexibility in frames the measurement does not have to be 100% exact, however a well fitting pair of glasses will be more comfortable and visually enhance your features if the frame width is observed. Check your frame width and PD when choosing your new Spex.
Sizing is displayed as (eg) 52 – 18 – 135 and can usually be found inside the arm of the frame. We grade the frames into small, medium and large taking all factors including frame width and bridge into account.
1st number is the Lens Diameter in mm. Measured horizontally at the lens midpoint.
2nd number is the Bridge Width. If this is too narrow for you, the glasses may sit too far forward of the nose and alter the vision. It could also be uncomfortable.
3rd number is the Temple or Arm of the glasses which extends from the front of the frame to behind the ears.
Frame or lens depth will affect the type of lenses that can be fitted. Single vision lenses can be fitted into all frames. Lens depth less then 26mm will not be suitable for progressives or bifocals. This is displayed on our website.
Check the Frame or lens depth also when you are looking for a style to enhance your features. For example, some face shapes do not suit round or very deep frames.
(See face shapes for more styling advice)
WHAT IS MY PD?
The “PD” (pupillary distance) is the distance between the centre of the pupils of each eye. The measurement is needed to ensure the prescription for your lenses is suitable for the selected frame. If you don’t know your PD, simply ask your optometrist to note it on your prescription especially if you are ordering progressives or we can measure in-store.
FRAMES AREN'T ALL THE SAME
Choosing a frame is the first thing that customers focus on when buying their new prescription glasses. Materials used in todays fabrication of frames are mostly durable and of consistent quality. Here’s a brief description of different materials used.
The most common premium material used in making eyeglass frames and also referred to as Zyl or cellulose acetate, the frames are available in many colours and patterns from solid to multi-coloured. Durable and colour fast Zyl is cost-effective and light weight. Acetate frames are easy for the optical dispenser to work with and are the traditional and recommended material for frames that will last the distance. The material when exposed to hot air will stretch or shrink to fit the lenses. Acetate is made from cotton seed fibers mixed with plasticizers and stabilizers.
Frames made of an alloy of mainly iron with some chromium, manganese and nickel. Unlike some other metals it will not react with your skin and it has a lot of flexibility and strength. Stainless steel is also resistant to corrosion and heat. Reasonably priced and readily available.
This is a new super light weight material used in eyeglass frames. A plastic titanium with memory it returns to its original shape. It is resistant to impact making it stronger and more durable. Due to its lightness and low friction qualities, it reduces pressure on the bridge of the nose and ears making for a very comfortable frame. Colours are solid and vivid.
Used for many years in manufacture of eyeglasses nylon is a thermoplastic processed by injection moulding and these days is blended with polyamides, co-polyamides and gliamides which make them strong and lightweight. It has good hypo-allergenic properties and is comfortable to wear. Nylon frames require a good deal of heat for lens insertion and adjustments.
A newer, high-tech metal that is high-quality. It is as much as 40% lighter then traditional metals and noted for its strength and durability. Titanium eyewear comes in many colours and has a modern look. Usually very expensive due to the special welding equipment needed in its fabrication.
Commercial aluminium has some silicon and iron in it making it hard and strong. Fairly light it can be a comfortable frame to wear. It is resistant to corrosion and achieves a high shine. Aluminium frames allow for many variations of colour and lends itself to unique designs.