5 Easy Steps to Purchasing Glasses Online
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1 5 Easy Steps to Purchasing Glasses Online 1. How to choose a frame that fits Frame sizes are usually in the format In this case, this means that the lens diameter is 50mm and the bridge distance is 20mm. You may use this as a guideline by comparing them to your own glasses 2. Understand your prescription and avoid common mistakes **Important** Your prescription may seem a little confusing at the first glance but in truth, its just a simple information once you understand the abbreviations used. Let's take it one step at a time. First, every prescription follows universal format. There maybe a few variations but we'll address them as we go along. Let's describe the basic information first. (a) Each prescription will have a left and right value for the correction of your vision. Within the prescription you may find the following boxes: "SPH" (sphere) The correction for long or short sightedness "CYL" (cylindrical) The correction for Astigmatism "AXIS" The axis for the correction of Astigmatism "ADD" The correction for reading which needs to be added onto the distance prescription. Sometimes an Add or Addition, always "+" value is included for us to decipher your reading prescription, but only if you require glasses for reading
2 (b) Your prescription may consist of both "+" AND "-" Values. SPH (Spherical) will consist of a + or power in 0.25 steps EG, -0.25, -0.50, -0.75, -1.00, etc... CYL (cylindrical) will consist of a + or power in 0.25 steps EG, -0.25, -0.50, -0.75, -1.00, etc... Axis will consist of a value from 0 to 180, BUT only when you have a CYL value. ADD will only consist of a + value as what it is suggested, an "addition". We add this value to your distance prescription if you need reading glasses or bifocals. Note : The single most common mistake when entering prescriptions online is selecting a "+"value instead of a "-" value or vice versa. So, please take your time and be careful.. 3. Common Abbreviations Plano, 0.00, Infinity They all mean exactly the same thing. NO CORRECTION is required. DS (Dioptre Spheres) This usually appears under the CYL box indicating that there is no astigmatism. OD This abbreviation may be used to reference your LEFT eye. PD (Pupillary Distance) This is the distance between the centre of one pupil to the centre of the other. This measurement is usually given in millimeters. Opticians may hesitate to provide you with this information as this is an indication that you are considering purchasing glasses online. However, one can quickly calculate this Pupillary Distance for ourselves using a school ruler and a willing friend. Here's how. Remove your glasses Have your friend sit directly opposite you, positioned exactly at eye level Remaining still, have your friend cover their OWN RIGHT EYE and position a ruler on the edge of your right pupil. Next, have them cover their OWN LEFT EYE and record your Pupillary Distance by measuring to the same position on your left pupil.
3 That's all there is to it. Here's an example - the Pupillary Distance here is 56mm Outside of United Kingdom, the prescription format maybe in the form of (-1.00) x180 - although this looks very different, its not. The first value is the SPH, the second in brackets is the CYL value, and the x180 is the Axis. Simple right? 4. How to choose the best lens for your eyes There are different types of lenses to choose from. It may be a little confusing initially but if you read on, you will soon unbaffle the mystery so that you can determine the best lens option for you own eyes. Lenses can be made in two materials Organic (Plastic) or Mineral (Glass). Most lenses sold today are of the plastic variety as they are lighter than glass. In some rare occasions when extremely thin lenses are required for very high prescriptions, glass can sometimes be the best option. Each lens has "Refractive index". This index has a direct relationship with the thickness of the lens. To the general public, many have the misconception that a 1.6 index lens will result in a pair of lens that is 1.6mm thick. This cannot be further from the truth. In fact, the higher the number, the thinner the lens will be. This is because materials that bend light more than others have a higher Refractive index and hence a shorter or longer focal length. This means that the same correction and focal length can be achieved from less lens (material), making them thinner.
4 Here's the secret key to choosing the best lens. Standard Plastic CR39 (1.5) Infinity Eyewear uses 1.56 on all standard lenses This is ideal for most prescriptions within the range of and Plastic (1.6) An ideal option for prescriptions within the range of and lenses are 23% thinner than the standard plastic option. Plastic (1.67) This is probably the most popular lens options. 15% thinner than the 1.6 and 25% flatter. Ideal for prescriptions within the range of and Plastic (1.74) The thinnest plastic lens available on the market. 50% thinner than the 1.5 standard plastic and 30% lighter than glass. Ideal for mid to high range prescriptions. Glass (1.7) Ideal for those looking for a budget thin lens option. Great for - power prescriptions up to However, glass is heavier than plastic and this increases the overall weight. Glass (1.8) Rarely used as its expensive - good for high power prescriptions. Glass (1.9) Rarely used as its expensive - excellent good for high power prescriptions.
5 5. Finally, the Lens Coating Anti Reflective Usually an anti reflective coating is referred to as an "MAR" (Multi Anti Reflective Coating). There are many benefits to using MAR. They are more aesthetically pleasing as they reduce the amount of light reflecting off your lenses especially during photo-taking sessions. Other benefits of using MAR include:- Reducing glare when driving at night Others can see your eyes instead of a reflective patch of light Filters out radiation from computer screens Reduces "power rings" the visible rings on the lens in high prescriptions which is caused by light constantly bouncing back and forth due to internal reflection. Provides UV protection Anti-static properties aiding lens cleaning That's it. You're now ready to embark on your first online glasses purchase. Remember, its simple, easy and most importantly... cost efficient!
Guide To Purchasing Glasses Online By. Spex4less.COM PREMIUM EYEWEAR
Guide To Purchasing Glasses Online By Spex4less.COM PREMIUM EYEWEAR 1 Index Introduction 3 Guarantee 3 Obtaining A Copy Of Your Prescription 4 How To Choose A Good Fitting Frame 5 Searching The Website
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