All About Lenses

Eureka Optical have possibly the largest selection of prescription glass lens options on the net at the lowest prices!

The information below is intended to give you practical guidance in selecting the right lens for you.

How do I select the right lens index?

If cost is a major consideration notwithstanding our low prices..then the selection is easy, you can just select the cheapest option (the US standard is 1.49 refractive index, and our standard is just above at 1.50 refractive index). You'll be happy with your choice, after all the standard lenses will be made to the prescription supplied. If your budget is tight and you are concerned with the cosmetic look (thickness), then you can add a 10% color tint at little extra cost and you'll be amazed at the improvement it makes giving the lens the appearance of a thinner profile.

Since development of the first lens, there have been many technological improvements in lens manufacture, that have made it possible to evolve the use of different materials such as hard resins and polycarbonate. Whilst these developments have allowed us to progress from glass lenses to safer "plastics", it has also allowed us to evolve a better performing lens for stronger prescriptions, apart from the obvious cosmetic improvements of wearing a thinner lens.

There are a few other considerations to bear in mind that may improve your use and enjoyment of your eyeglasses, and we have summarised these below to guide your selection.

Should you be concerned for the cosmetic look of your lenses (rather than strictly price considerations) you will probably decide to choose a higher index lens. If you decide to choose ultra thin lenses, then you should be aware that if you choose half frames it is better not to select  "Super Ultra 1.74 thin lens", as there is simply insufficient room to cut a groove on the edges to carry the necessary support filament. In other words you need a full frame to successfully accomodate the ultra thin lenses.

To some extent the thinness of the thinnest lens (or any inbetween) will be determined by the prescription. What may be wafer thin to one one prescription, may due to the requirements of a strong correction of the prescription, be different to another less strong prescription. If you have a particularly strong prescription, and want to achieve the thinnest result, then probably a 1.60 index lens may well be sufficient. Otherwise you may find it hard to understand when you receive them,  that there may appear to be visually little difference in thickness in going to the higher index.

Also it is worth noting that the thinner lens benefits will be purely cosmetic, unless your prescription is suficiently strong. It does not follow that the lenses will be clearer using a higher index unless your presciption is better suited to a higher index.

Lenses are usually described as being for Single Vision use, or Multifocal use.

Single Vision use is simply a lens with a sole specific use e.g. Reading, Computer, or  Distance.

Multifocal (is the combined term for Bifocal, and Progressive lenses) combines two specific uses within the same lens i.e. distance and reading. The bifocal lens does this by having a clear definition between the two uses, by  featuring an "invisible clear line" on the lens. Above the line is the distance prescription and below the line is the reading presciption.  The progressive lens is basically a bifocal lens without a line, which progressively moves you from one prescription magnification to the other.

A summary guide to lens selection:

1.50 High Index Standard Single Vision Lens, and Progressive Lens

A general all purpose lens, but suited in particular for SPHERE : (-3.00 to +2.50) and CYLINDER : (-3.00 and below)

1.56 High Index Thin Lite Single Vision Lens, and Progressive Lens

Light and comfortable to wear our High Index 1.56 Lens allows for reduction of the lens thickness of stronger prescriptions. Reccomended for prescription range of SPHERE (-3.50 to +2.50) and CYLINDER (-3.00 below). Around 10% thinner than the 1.5 High Index Standard Lens.

1.58 High Index Polycarbonate "Sports" Single Vision Lens, and Progressive Lens

Much thinner and lighter than conventional lenses makes it a popular all round choice, polycarbonate is ideal for active use (reccommended for children, safety glasses, and sports activities in particular) as it ten times more impact resistant than other "plastic" lenses. Made from material developed for bullet proofing, to provide high impact protection. If you are unsure, but  want a thinner lens, polycarbonate is an excellent choice at surprisingly little extra cost. About 17% thinner than the 1.5 Index Standard.

1.60 High Index Extra Thin Single Vision Lens, and Progressive Lens

Lighter and more comfortable to wear, the 1.60 index reduces the lens thickness of high powered prescriptions. Reccomended for prescriptions range of  SPHERE (-4.00 to +3.00) and CYLINDER (-3.00 and below). It is 20% thinner than the 1.5 High Index Standard Lens, and 25% lighter.

1.67 High Index Ultra Thin Single Vision Lens, and Progressive Lens

Reduces the thickness of the lens for high powered prescriptions, and therefore lighter and comfortable to wear. Reccomended for prescriptions range of  SPHERE (-5.00 to +4.50 and above) and CYLINDER (- 4.00 and below). Again thinner than the High Index 1.60 by around 15%, and also 15% lighter.

1.74 High Index Super Ultra Thin Single Vision Lens, and Progressive Lens

The thinnest and lightest available for high powered prescriptions. These lenses are light and comfortable to wear.                Reccomended for prescriptions range of  SPHERE ( -8.75 to +8.00 and above) and CYLINDER (-5.00 and below).