Precise Pupillary Distance (PD) Measurement

Pupillary distance, commonly known as PD (Pupillary Distance), is the distance between the centers of the two pupils. This seemingly unremarkable number actually plays a decisive role in the comfort and visual effect of wearing glasses. If the PD measurement is inaccurate, the optical center of the glasses will not match the pupil center, causing problems such as visual fatigue, dizziness, and blurred vision, just like wearing ill - fitting shoes that make every step uncomfortable.

To help you solve this problem, here is a simple and practical method - the Credit Card Assisted Method. The specific steps are as follows: First, find a standard - sized credit card and gently align its edge with the center of one eye's pupil, keeping it horizontal. Then, in a well - lit place, keep your head steady, look straight ahead, and take a clear photo with a mobile phone or camera. After that, use image - processing software to enlarge the photo and carefully measure the distance between the centers of the two pupils. Make sure the measurement error is less than 1mm, as this small error may be magnified during glasses fitting and affect the wearing experience.

Deciphering the Optometry Prescription

When we get an optometry prescription, the dense letters and numbers on it may seem confusing. Don't worry. Just master a few key parameters and you can easily understand it.

First, we've already introduced "PD" (Pupillary Distance) in detail. It's the pupillary distance, a key data for glasses fitting, determining the position of the optical center of the lenses. It must be measured accurately and remembered.

"OD" is the abbreviation of the Latin "Oculus Dexter", representing the right eye (also abbreviated as "R" in English, i.e., "Right"); "OS" is the abbreviation of "Oculus Sinister", representing the left eye (abbreviated as "L" in English, i.e., "Left"). These two identifiers clearly distinguish the degree information of the left and right eyes, allowing us to clearly know the vision condition of each eye. For example, "OD - 3.00" on the optometry prescription means the right eye is nearsighted by 300 degrees; "OS - 2.50" means the left eye is nearsighted by 250 degrees.

"ADD" stands for Addition, mainly used as a numerical reference for progressive multifocal lens fitting. As people age, the eye's accommodative power declines, and problems such as blurred vision when looking at near objects may occur. ADD is the absolute value of the difference between the distance - vision degree and the near - vision degree.

During the optometry, the doctor will first measure the diopter required for distance vision (distance - vision degree), and then the diopter required for near vision (near - vision degree), and the difference between the two is the ADD value. For example, if the distance - vision degree is - 2.00 and the near - vision degree is - 1.00, then ADD is 1.00. This value is crucial for choosing the right progressive multifocal lens, helping us to get clear vision at different distances.

Selecting the Lens Combination

After accurately measuring the PD and understanding the optometry prescription, the next crucial step is to select the lens combination. For people with high myopia (degrees of - 6.00 and above), we strongly recommend choosing 1.74 high - refractive - index lenses with anti - oil coating. This combination is a perfect match, bringing us an ultimate visual experience and convenience.

Let's talk about 1.74 high - refractive - index lenses first. The refractive index of a lens is an important indicator to measure its optical performance, directly affecting the thickness and weight of the lens. Just like the clothes we wear daily, light and thin materials make us move freely and comfortably. For high - myopia patients, 1.74 high - refractive - index lenses are like that light and thin piece of clothing.

With a high refractive index, they can effectively reduce the thickness and weight of the lenses. Imagine the original thick lenses pressing on the bridge of the nose, making it sore and painful after a long time and also affecting the appearance. While 1.74 high - refractive - index lenses can make the lenses thinner and lighter, not only making them more comfortable to wear, reducing the burden on the nose and ears, but also making the glasses more beautiful, perfectly matching various fashionable frames and easily enhancing the overall image.

When paired with an anti - oil coating, it's even better. In daily life, lenses are easily contaminated with oil, dust, and fingerprints. These stains not only affect the clarity of the lenses but also blur our vision, just like a window covered with dust making the beautiful scenery outside dim. The anti - oil coating can form a special protective film on the surface of the lens.

This protective film, like the surface of a lotus leaf, has strong oil - and water - repellent properties, effectively resisting the adhesion of oil, water stains, and dust. When oil or water droplets fall on the lens, they cannot stay on the surface but slide off quickly, keeping the lens clean and transparent at all times and providing us with a clear visual effect. Moreover, the anti - oil coating can also enhance the wear resistance of the lens, extending its service life and making our investment more valuable.

Quality Acceptance Standards

Lens Authenticity Detection

When we happily receive the glasses bought online, the first thing to do is to detect the authenticity of the lenses to ensure we get genuine products. Here is a simple and effective method - the UV Lamp Irradiation Method. Just prepare a UV lamp with a wavelength of 365nm, which can be easily bought online or in a hardware store. Turn on the UV lamp, in a dark environment, aim it at the lens surface, about 5 - 10 cm away from the lens, and keep it steadily irradiating.

If the lens is genuine, under the irradiation of the UV lamp, a clear snow - like pattern anti - counterfeiting mark will appear on the lens surface. It's like giving the lens a unique "ID card", and only genuine lenses have this special "identification". Counterfeit lenses will not show such a clear anti - counterfeiting mark, or the mark is blurred and irregular, just like the logos of fake products are always full of flaws. Through this method, we can quickly and accurately judge the authenticity of the lenses and protect our vision.

Stress Test

In addition to detecting the authenticity of the lenses, the stress test is also a key part of checking the quality of the glasses. The stress test mainly checks whether the lens has uneven stress due to the squeezing of the frame during the assembly process, affecting the visual effect and wearing comfort. If the stress of the lens is too high, we may experience discomfort such as dizziness and distorted vision when wearing it, like looking at the world through a distorted glass, making everything seem unreal.

The specific operation method is as follows: Prepare a pair of polarizers, which can be removed from old polarized sunglasses or bought online as special testing polarizers. Place the glasses horizontally on the polarizer, ensuring that the lenses fit the polarizer completely. Then, observe the lenses from different angles and pay attention to whether rainbow - colored stripes appear on the lenses.

If no rainbow - colored stripes appear on the lens, or only a very small number of slight stripes appear, it means the lens assembly is qualified, the stress distribution is uniform, and it can provide us with a clear and stable visual experience. On the contrary, if a large number of obvious rainbow - colored stripes appear on the lens, it means the lens has a large amount of stress, and there may be problems with the assembly. You need to contact the merchant in time for handling.

After - sales Guarantee

When buying prescription glasses online, a complete after - sales guarantee is our "peace of mind", so that we have no worries. We offer a 30 - day no - reason return and exchange service for quality problems. Within 30 days after receiving the glasses, if you find any quality problems with the glasses, such as lens wear, frame breakage, or welding failure, just contact our customer service team, and we will provide you with a free return and exchange service. We will bear the round - trip shipping costs for returns and exchanges to ensure your rights and interests are fully protected.

We also provide a one - year warranty service. During the warranty period, if the glasses have quality problems caused by non - human factors, we will repair or replace the parts for you free of charge. Whether it's lens delamination, frame deformation, or loose screws, they are all within our warranty scope. We have a professional after - sales team with rich experience and excellent skills, who can quickly and accurately solve your problems and keep your glasses in the best condition.

To better serve you, we also provide comprehensive online consultation services. During the purchase process, if you have any questions about the interpretation of the optometry prescription, the selection of lenses, the style of frames, etc., you can contact our customer service staff at any time. They will answer you immediately and provide professional advice and guidance. Our customer service team is available 365 days a year, so you can get timely help whether you are in the busy working hours during the day or in the leisure time at night.

All products on our website have a discount starting from 10%. The higher the order amount, the greater the discount. This means that the more expensive the glasses you buy, the more discount you can enjoy. For example, if you buy a pair of glasses worth $100, calculated at a 10% discount, you can save $10. If the glasses you buy are more expensive, reaching $200, the discount may be even greater, allowing you to enjoy more benefits. Such a discount policy enables you to buy high - quality glasses while saving money, truly getting value for your money.

If you think what I wrote is good, remember to subscribe to our website! So that you can enjoy the latest discount information.