Choosing eye glasses
As we get older, our eye’s ability to adjust between objects that are near and far away decreases, meaning that our overall vision deteriorates! Glasses are made to correct the refractive error in your eye. This buying guide has been created to help you understand the different types of glasses and to choose the right ones for you. Your decision will depend on your preferences, your facial shape and the degree of your visual impairment.
What is a diopter?
A diopter (also called “dioptre” and usually abbreviated as “D”) measures refraction. The strength of the eyeglass lenses is always measured in diopters and indicates how much a lens has to break light to normalise your vision. Negative dioptic values correct myopia (short-sightedness) and positive dioptic values correct hyperopia (long-sightedness). The table below will give you an overview of your degree of visual impairment:
Different types of glasses
1. Reading glasses
If your vision becomes blurry at distances of about 35 to 50cm you definitely need reading glasses. These glasses correct presbyopia, which is an impairment occurring with advancing age. It’s a natural condition which appears by the age of about 45 years.
The general formula below will help you to determine your dioptic values while choosing your reading glasses:
If you were already short or long sighted before the age of about 45 years you have to add the following dioptic values:
Long-sightedness: If you had correction eyeglasses with 2.0 diopters and need reading glasses at the age of 50 years, your needed dioptic value would be 2.75.
Short-sightedness: If you already had correction glasses with – 2.75 diopter and need reading glasses at the age of 50 years, your needed dioptic value would be 0. This means that presbyopia would be balanced and you wouldn’t need glasses anymore.
Bifocals balance both long-sightedness and short-sightedness. The advantage of this type of glasses is that you don’t need to have two different pairs e.g. reading glasses for reading and correction glasses for driving your car. However, the disadvantage is that the dividing line between near and distance vision is clearly visible.
3. Varifocal glasses
Varifocal glasses balance both long-sightedness and short-sightedness. They are needed by the age of about 45 years, when presbyopia appears. Like bifocals, varifocal glasses are a compromise between reading and correction glasses.
Advantage: Thanks to the three different zones (distance vision, intermediate distance and near vision) the dividing line between each vision is not visible on the lens.
Disadvantage: Varifocal glasses can make you dizzy or cause headaches in the first few weeks because your eyes have to get used to them.
Sunglasses protect your eyes from harmful sunrays. When it comes to choosing your sunglasses you have to consider both the lenses’ tint and the width of the frame.
Ralph Lauren sunglasses £103.75
Ray Ban sunglasses £125
A wide frame gives your eyes more protection from the sun. In this case, the sunglasses from Ralph Lauren let less sunrays penetrate through the lens than the sunglasses from Ray Ban.
5. Sports glasses
Sports glasses are obviously made for different types of sports. You will find suitable glasses for almost every sport activity such as cycling, swimming, diving etc.
Different glasses designs
You will find a large range of various designs such as retro, vintage, elegant or classic. However, nerd and aviator glasses are most popular.
Nerd glasses have a distinctive, often black colored frame and are currently a very popular design.
Rayflector nerd glasses £4.99
Aviator sunglasses are also a popular fashion accessory. When buying aviator sunglasses it is recommended to choose ones with 50% a tint or with self-coloring lenses to better protect you from sunrays.
Types of lens
You can buy your frame and your lenses separately or just change the old lenses if you already have sunglasses. There are two different types of lenses, namely self-coloring and polarized lenses.
This type of lens adapts automatically to the current lighting condition. The lenses’ tint depends on the intensity of UV radiation. Most online shops offer self-coloring lenses for every type of glasses.
Polarized lenses are particularly helpful in summer because they reduce light reflections that come from sunrays. The advantage of polarized lenses is that your eyes get less tired because they don’t need to adapt to a fluctuating lighting condition.
Which glasses are best for which facial shape?
The table below illustrates which glasses are best for oval, round, heart-shaped and rectangular faces and what affect the different glasses have on your face: