Pupillary distance: what need to know

Pupillary distance (PD) is the distance between your pupils that determines comfort and how well your glasses fit. Having a PD is just as considerable as your prescription when it comes to ordering a new pair of prescription glasses or sunglasses. The average value of the pupillary distance for an adult is about 63 mm.

After all, measurements can vary widely – between 51 mm and 74.5 mm for women and 53 mm and 77 mm for men. There are two main methods of PD measurement: single PD and dual PD.

Single PD is the pupil-to-pupil measurement between each eye. Double PD is the measurement from the nasal bridge to each eye.

Double PD is considered the most accurate. PD is especially important when fitting glasses with progressive lenses, which require precise alignment of the lens with the pupil to ensure comfortable vision at all distances.

Can you measure it yourself?

You can measure the pupillary distance yourself. For this, you need a millimeter ruler and a mirror. If there is no ruler, you can print a particular scale for measurement, but you first ensure that the printer doesn’t distort the scale.

The room should be well lit. Stand in front of the mirror at a distance of 20 cm. Locate the ruler above the eyeballs, parallel to the eyebrow line. Held the head straight to obtain more accurate measurements.

First, you should close one eye and place zero on the ruler opposite the left center of the pupil. The more precisely the center is determined, the better the result is.

Next, you should open the second eye and find the division on the ruler, which will be accurate in the middle of the pupil. At this time, you can’t move your head or the ruler. Direct eyes to the mirror for the measurement to be correct. The obtained data in millimeters is the pupillary distance. You should make measurements 3 or 4 times.

Another person’s help

You can measure with the help of another person. Following simple rules, you can understand how to measure the pupillary distance with an assistant. For this, it’s necessary to face each other. The distance between people should be 20 cm. A larger or smaller interval will distort the result.

The measured person should look over the assistant’s head. The head should be lower than the eyes of the subject. Look at an object that is at a distance of 3-6 meters from a person. For the accuracy of the measurement, you can’t move, move your head and turn your eyes. You should fix the view. You should position the ruler above the eyes parallel to the eyebrow line. Zero should be set in the center of the pupil of one eye and determine at what distance the other pupil will be.

Examination by an ophthalmologist

Measuring the pupillary distance at an ophthalmologist will show a more accurate result. Choosing glasses, the doctor holds a special ruler at different intervals. It depends on the degree of nearsightedness or farsightedness.

Pupilometer

Ophthalmologists use a pupillometer to determine the diameter of the pupils and the distance between them. The modern device is rich in settings and guarantees the high accuracy of the result. Compared to other methods, the pupillometer has the following advantages:

• quick and accurate result;

• accuracy is not affected by uncontrolled movements of the pupils and the degree of illumination of the office;

• the result is displayed on the device display.

The device can measure from the nasal bridge to each pupil. It shows data for asymmetry, farsightedness, and myopia. The ability to measure the pupillary distance helps to adjust it when using optical devices. Some of them require settings to see the images.

Transition lenses and prescription sunglasses: main advantages, disadvantages, and differences

Transition lenses 

Glasses with transition lenses change their color, adjusting to the lighting conditions: in bright light, they darken, and in a dark room they remain transparent. This effect is ensured by a special coating with photochromic properties. It is they react to UV, activating their protective properties and reducing light transmission. The degree of darkening of such lenses in some models reaches 85%.

Glasses with transition lenses combine the benefits of corrective and sun protection optics. This is very convenient for people with low vision who can’t protect their eyes on a sunny day because they have to wear corrective glasses. Also, transition lenses are recommended for people who suffer from eye diseases. 

 

Main advantages 

• “Two in one” – glasses with transition lenses make life easier for people who need vision correction. You no longer need to squint from the sun or wear sunglasses to the detriment of good visibility. Transition lenses provide both the necessary correction and protection from bright sunlight.

• Help for people with eye diseases and photosensitivity – transition lenses provide relief for people who suffer from diseases that cause increased sensitivity to light. Glasses that quickly adapt to changes in lighting effectively protect the eyes from pain and discomfort. 

• Special lenses for drivers – glasses with such lenses react not only to UV radiation but also to visible light, due to which the lenses darken even when not directly exposed to the sun.

Main disadvantages

• The degree and speed of darkening depend on the ambient temperature. The reaction is faster in warm weather and slower in cold weather. At temperatures above 30 °C, the lenses don’t darken completely, but by 90-95%, which can cause discomfort to residents of the southern regions. In the cold, on the contrary, the glasses give out their maximum, which is not always convenient when it is partly cloudy or walking through the forest with constantly changing lighting.

• Limited range of colors – unlike sun-protection and tinted optics, transition lenses have a small palette of possible dimming colors. 

• If you leave your glasses in an enclosed space in hot weather in direct sunlight in a car or on a window, the protective coating may be damaged.

Prescription sunglasses  

Most people who wear glasses often experience discomfort with the onset of sunny weather. This problem is especially true for people who drive a car or spend a lot of time outdoors. An excellent summer solution for people with low vision will be sunglasses with prescription lenses. These are glasses two in one: glasses for vision and sunglasses at the same time. In addition to providing a comfortable stay in the blinding sun, such glasses protect against harmful UV radiation and have several other advantages.

Why do we need prescription sunglasses if there are transition ones?

It would seem, that why would someone need a half solution if there is a complex one? But there are a few subtleties that you need to be aware of to make an informed decision.

• As mentioned above, transition lenses have residual tint. Not everyone likes it. Many people need the most transparent lenses.

• Not everyone is comfortable waiting for the lenses to darken / clear.

• Well, and most importantly, prescription sunglasses have much more options for colors, shades, tints, color combinations, and so on.

How to take care of sunglasses

Useful tips to take care of your sunglasses

 

The frames of sunglasses can wear and deform over time, and the lenses can get dirty and scratched. All this leads to the fact that wearing them becomes not as comfortable as before. And in some cases, such breakdowns can even ruin your eyesight. To prevent this from happening, you need to take care of your glasses and do it right.

Sunglasses, like any other accessory, require careful care and proper use, and then they will be able to please their owner much longer.

Dust, dirt, grease, fingerprints, falls – all these factors affect the condition of any glasses.

For the glasses to serve as long as possible, you need to follow a few simple rules that are available to each of us.

 

How to take care of your sunglasses

• Handle glasses with care. That is, carefully put on and take off the accessory, making sure that you don’t stretch or bend the temples and nose pads.

• Put on and take off glasses with both hands, holding them by the temples.

• When taking off your glasses, put them in a hard sunglasses case. It is the best way to prevent damage, scuffs, and cracks.

• Avoid putting glasses with lenses down on hard surfaces (this applies to any glasses, not just sunglasses) – scratches may occur.

• Sunglasses must not be exposed to shock or vibration.

• Lenses, as well as frames, are not intended for contact with gasoline, chemicals, and other aggressive environments.

• Don’t swim with sunglasses in salty sea water, as it can adversely affect the color and its uniformity.

• Sunglasses keep the operational characteristics in the range of temperatures: from – 50°C to + 45°C.

 

How to clean sunglasses

For daily care, you will need a special microfiber cloth. It perfectly removes fingerprints and small dirt. Due to its structure, it can’t scratch your lenses.

If there is serious contamination on the lenses or frames, it is necessary to use special sprays.

We also recommend purchasing wipes with a special cleansing impregnation. It has an antibacterial effect and perfectly copes with any pollution.

Now that you know how to take care of your lenses and frames, you can prolong the life of your sunglasses.

Best selling Sunglasses

sale
sale
sale
sale
sale
sale
sale
sale
Out of stock