Spectacle Frame Selection Guide matching to Your Face

Spectacle Frame Material

Around 40% population is having refractive error globally which can be corrected by using glasses or contact lenses (if someone likes it). So we are discussing about glasses frame – which one is good for you or how to select a spectacle frame?

Eyeglasses frames are available in different styles, sizes, and materials. New material and technology have made the frames more comfortable and light-weighted.

Most population want a fancy frame and eyeglasses with a reasonable or low price as they know the fact that they need to change glasses every 6-12 months. Changing of glasses is purely dependent on your age and profession.

If you are under 20 years then your glasses number may change every 6-12 months. If you are between 20-38 years then you may need to change glasses 1-2 years. If you are falling in the age group 40 years or more then you need to change your glasses every year as you would need reading correction in your glasses. In the case of myopia, person need to use glasses only for distance and can remove glasses for near even after the age of 40 but in case of hypermetropia person need to change glasses every year (sometimes 8-9 months also) as their accommodation is going to be relaxed.

There are some more factors which we need to consider while selecting a frame ie. weight of the frame, the flexibility of frame, the strength of the frame, and corrosion-resistant. In today’s fashion time there are several types of frames available in the market: Plastic frame, metal frame, and rimless.

Plastic frames are very less expensive and the most popular choice. These frames come in a variety of colors and styles. Soft plastic frames are good for infants and small children and likely to hurt the child. Plastic frames are made up of Zyl (zylonite, acetate or cellulose acetate) or propionate, polycarbonate, nylon, polymide, optyl (epoxy resin) and carbon.

Plastic frames are further divided:

Cellulose acetate (Zylonite): most commonly used in frames and relatively inexpensive. This material is easily adjustable but becomes brittle with age. These frames are available with the name of ‘Zyl Frames’.

Cellulose acetate propionate: This material is light weighted and injected in a mould to form an intricate design. The person should be careful while heating and adjusting the frame. Overheating may unshaped the frame and would be difficult to fit the lenses.

Optyl: Optyl is almost the same weight as cellulose acetate. This material is hypoallergenic so the wearer will not have skin-allergy. Adjustment of the frame would be difficult as the material may go back its own shape and there is a possibility to increase the breakage of the frame.

Nylon: Nylon frames are flexible, lightweight, and unbreakable. Nylon frames are used for sports and safety applications. Nylon frames are typically made of gliamides, grilamid, or trogamid materials and are resistant to hot and cold temperatures. Popular wraparound styles are made with nylon material. Nylon frames are available only in dark colors. These frames are having difficulty during adjustment and over a period of time frames become brittle.

Metal frames are further divided:

Titanium: Titanium frames are flexible, light weight, strong and corrosion-resistant. These frames are hypoallergic in nature but good for people who are allergic to some metal such as Nickel. These frames come in trendy and fashionable range but they are expensive.

Stainless Steel: Stainless steel frames are stronger but not light weighted as the Titanium frame. It is less expensive and corrosion-resistant frames than other metal frames.

Aluminum: Aluminium frames are light weight, strong, flexible, and corrosion-resistant and provide excellent durability. Aluminum frames creates unique looks due to its high-end designs.

Beryllium: Beryllium is light weight, strong and flexible. It is a little less expensive and alternative to the titanium frame. It is a good choice for people who spend more time in or around salt water.

Monel: Monel is a mixture of one-third part of copper and two-third parts of nickel. This is a high yield alloy with which a variety of different shapes of frames can be made without losing strength but some people may get allergy with this metal. To protect the skin allergic reaction frames have a special coating.

Flexon: Flexon (an alloy of titanium) is a very flexible material as its name suggests. It is light weight, corrosion-resistant, and hypoallergic. Flexon frames that bend or twisted and comes to its original shape. These types of frames are a good choice for active kids.

Rimless frames:

Rimless or drilled frames are lightweight. Trivex or polycarbonate lenses work with these types of frames.

Unusual frames:

People who want a unique style of frame and want to spend money on it. Frames come with precious stones, gold plate, silver, leather, wood, and bone (buffalo horn).

There are ready and custom-made glasses:

Ready-made glasses: These glasses are one-size-fit for all and less expensive. These types of glasses can be purchased from an optical store easily. Readymade glasses are not available in bifocal or progressive lenses.

Custom-made glasses: Custom-made glasses are prescription glasses for individual eye and are made according to the prescription. Bifocal or Progressive lenses can be fit according to Interpupillary distance.

Select frame as per your prescription, lens shape, and size will help you to save money and prevent skin allergy too.

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Importance of Interpupillary Distance in Spectacles

Importance of Interpupillary Distance

Globally approximately 145 million people of the total population and approximately 40% of India’s population is having an uncorrected refractive error (means need a pair of glass/spectacle).

Refractive error is one of the most important ocular conditions that are affecting all age groups and a priority under the VISION2020 initiative. Most refractive errors can be easily corrected at the primary care level with the help of spectacles. Uncorrected refractive error is the second leading cause of vision impairment in developing countries (including India).

Interpupillary distance (IPD) is the distance between the centers of your two eyes (center of corneal reflex) which is measured in millimeter. IPD can be measured monocularly and binocularly. Monocular IPD is the distance between the center of each eye and the center bridge of the nose. Monocular IPD may be slightly different for each eye due to anatomical variation and is dependent on your eye placement. An adult IPD usually remains more than kids IPD. IPD measurement is required for all types of spectacles including buying spectacles for distance or near. The near IPD is usually smaller than distance IPD due to convergence of the eyes together to fuse an object at near.

Different ways to measure IPD:

•    Ruler and torchlight (old method)
•    Pupillometer
•    Essilor Visioffice (USA)
•    Eye-Ruler 2 (USA) 

•    Zeiss i-Terminal2

IPD Measurement with Ruler and torchlight

Examiner should be exactly in front of the patient maintaining the same eye level height and holding a ruler at arm's length distance. Examiner closes his right eye and the patient must be looking at the examiner’s left eye with his right eye and put the ruler at the patient’s nose bridge area (for better stability) while aligning ‘0’ at patient’s center of the right eye. And without moving off a ruler examiner should open his right eye (after closing his left eye) and the patient must be looking at the examiner’s right eye with his left eye. Now measure the distance between both eyes center with ruler – this is your distance IPD. Average distance IPD may fall in the range of 56-66mm. The drawback of this method is parallax may skew measurement, examiner PD and patient’s PD must be very similar and the patient’s pupil must have the same size.

Another way to measure IPD is the distance between the right eye’s outer limbus to left eye’s inner limbus. With this method, IPD measurement may be inaccurate.

IPD measurement with Pupillometer

IPD measurement with pupillometer is more convenient. A Pupillometer has forehead rest, nose bridge, dial to change the distance to focus, display for monocular and binocular PD. Putting dial at infinite while using pupillometer over patient nose and aligning forehead rest. Now patient must be looking at small light inside the pupillometer and the examiner should align the measuring slide (a line or bar) until vertical lines should coincide with the corneal reflex. And read the reading in the display for monocular and binocular IPD. 

Essilor Visioffice2 (USA)

This device is faster than using manual measurement and takes all necessary measurements for personalized progressive lens and provides numerous solutions to select the lenses and frames. This device assesses the different measurement centers of eye rotation, the distance between pupils, the dominance of eye, reading distance, pantoscopic tilt, the fitting height of the lens, and frame parameters ie. wrap angle, A, B, and DBL.

Zeiss i-Terminal2

Zeiss i-Terminal2 is faster than using manual measurement and captures and calculates the patient’s required parameters with the click of a button. This device enables the measurement of highly ametropic patients through vergence control technology.  Measurement can be taken for any type of frame including large-size sunglasses and sports frames. It can measurement all height persons (children, taller or wheelchair person) ranging from ~120-208cms.

IPD is used to align the center of eyeglass lenses with the center of your eyes, which will give you a comfortable and relaxed vision. If the centers of eyeglass lenses are not aligned properly as per your eyes centration, then you may experience eyestrain, headaches, distorted vision, double vision, blurred vision, and/or an inability to wear your eyeglasses for a longer duration.

There are so many spectacle users (patients) who complain of eye strain. Many spectacle users are unsatisfactory that is the result of incorrect estimation of the IPD for distance and near. So it is an important While making a pair of glasses the dispensing professional need to measure Interpupillary distance (IPD) of a person.

IPD measurement is not the part of an eye examination but the IPD measurement is the responsibility of the dispensing professional and it is an important part of a spectacle prescription. Other spectacle dispensing services includes selection of an appropriate frame, lens type, lens thickness and coatings, adjustment of the spectacle frame, and proper alignment of the bifocal or progressive lens height.

Sometimes being perfect IPD alignment and proper spectacle lens fitting still patient complain of eye strain or unsatisfied. What could be the next to find for eye strain or unsatisfactory? So it is very useful scientifically to check the front and back curvature of the lens, coating of the lens, design (aspheric or conventional) of the lens of old glasses as sometimes spectacle users may not very satisfy with new glasses because of this. Sometimes new spectacle lens may have different front and back curvature, different coating of the lens, and design (aspheric or conventional) of the lens.

There are some more factors including frame size (bigger or smaller size over face), pantoscopic tilt (the amount of tilt on the front of the frame), wrap angle (the amount the frame is curved towards your face) and frame alignment over the face which can lead eye strain or unsatisfactory.

There are some other measurements that your optician will take when fitting you for progressive or multifocal lenses. There are two important key measurements - the IPD and the segment height must be checked while fitting a multifocal lens. These two measurements will be providing a comfortable vision with lesser adaptation time.

Each spectacle lens manufacturer is having its version of customized progressives. Near-pupillary distance measurement is also important in progressive addition lenses as these lenses are having customization instead of being standard. There are few other measurements including the vertex distance (the distance between the frame and the cornea), the pantascopic tilt, and the wrap angle to be checked while making a selection of a frame. The latest progressive lenses are more user friendly, giving a wider area of the field of vision and are generally easier to adapt to, especially for those with higher power prescriptions.

In my practice, if any patient complains of eye strain, double vision (shadow feeling while watching TV, or reading text at near), headache after wearing new glasses then my first check would be refraction (repeat power) check-up, IPD measurement, vertex distance, pantoscopic tilt, etc. Most patients are satisfied with repeat refraction and IPD measurement and their comfort changes after reassuring these two checks.

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Myopia - How to correct

Myopia correction options

 

 Myopia or Nearsightedness is a vision condition in which a person can see near clearly but have difficulty seeing far objects (ie watching TV, a board in the classroom, while driving, etc).
   If the eyeball size becomes bigger or cornea (black eyeball) is more curved than normal, it causes myopia. The exact cause of myopia is still unknown, but there is an increased chance to get myopia hereditary if one or both parents are having myopia. Even though the tendency to develop myopia may be inherited, but the actual development of the eye may be affected by how a person uses his or her eyes. If someone spends more time reading books, intensive usage of computers and digital screens, or doing continuous near work for a long time may progress myopia rapidly.
   Generally myopia occurs in school-age children due to continuous growth of eyes and progresses until about age 20-21 years. Myopia may also develop in adults due to visual stress, during pregnancy, and health conditions such as diabetes.
Myopia may occur due to environmental factor or other health issues:
• Some persons may experience difficulty seeing far objects in dim light or night time due to low light makes it difficult to focus properly or increase pupil size in dark conditions allows more unfocused peripheral light rays to enter in the eyes.
• Some person who does excessive near work continuously without maintaining breaks may find difficulty to focus far objects in pseudo-myopic condition, caused by overuse of eyes’ focusing mechanism. However constant visual stress may lead to a permanent decrease in distance vision over some time.   
   An early indication of developing cataracts or change in diabetic level or during pregnancy may have symptoms of myopia.
Myopia can be corrected with glasses, contact lenses, surgically, and vision therapy for people with stress-related myopia.
Eyeglasses are the primary choice of myopia correction. Depending on the amount of myopia you may need to wear glasses for all the time for watching TV or driving a car.
   Contact lenses, are the next choice of myopia correction, provides a clearer and wider field of vision than glasses. Contact lenses are worn directly over eyes but need hygiene and care maintenance.
   Ortho-K or Corneal refractive therapy (CRT) is the other nonsurgical option to correct myopia. People with mild myopia can be obtained a clear vision for most of their activities. In this procedure, a series of specially designed rigid contact lenses placed over the cornea during sleep or overnight to gradually reshape the curvature of the cornea. The lenses are placed on the cornea to flatten it centrally.    

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Eye care tips

Your Eye's good vision help you perform well – at home or at work. It is important to take few simple steps to make sure that your eyesight at its best. Periodic eye exam is the best way to maintain good eyesight. 

Your eyes are unique and have their own set of nutritional need.

Choose food which is rich in antioxidants like vitamin A and C, food like green leafy vegetables, omega-3 fatty acids (good for macula health – the central part of retina) as part of your healthy diet.

Inadequate intake of antioxidants, smoking, and consumption of alcohol or saturated fats may create free-radicals reaction that can harm macula as age grows older. High fat diets can deposit in retinal blood vessels and slow down blood flow in retinal blood vessels which can cause decrease or loss of vision.

Body and eye exercise improves blood circulation, which improves oxygen level in blood and eyes that removes toxins.

You should have sound sleep at night for 6-8 hours that will make your performance better at home or work and will support the health of your eyes.

Always keep your hand clean, it is very important especially when it comes to your eyes and mouth. If you are contact lens user, before insertion and removal of contact lens – wash your hands with mild soap and dry with a lint-free towel. Otherwise germs and bacteria that come from your hands can cause an eye infection, cold and fever because whatever is on your fingers goes right in to your eye’s surface and mouth.

Smoking exposure, may increase oxidative stress level, may be risky for health conditions too.

Everyone should use ultraviolet (UV) protected sunglasses to protect eyes from harmful UV light. Choose sunglasses with both UVA and UVB protection. Wearing peaked cap or hat will reduce the amount of UV radiation entering in to eyes.

We live in a technology-run world, which means that a lot of our time is spent in front of a screen. In everyday life, we can’t live without digital screen and our screen usage has been increasing day by day. These devices are exposing your eyes to blue light because the wavelength emitted is near the bluer part of the spectrum. Lutein and Zeaxanthin are eye nutrients, obtained from diet and supplements, that are concentrated in the macula (the central part of retina) and help filter blue light.

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Eye care tips for kids

There are several tips you can follow so that your child's eyes remain healthy and see clearly from birth through the teen years.

Eat right both during pregnancy and after so that your baby will be healthier.

Provide nutritious meals with fruits, vegetables, nuts, and fish (for non-vegetarian). These foods contain key antioxidants and nutrients such as vitamin C, vitamin, E, zinc, omega-3 fatty acids, and lutein, which are linked to eye health. 

Provide your child with age-appropriate toys that are free from sharp edges.

Give your child toys that encourage visual development.

Watch your baby for signs that the eyes are crossed or turned out/in.

Look at your baby for any dullness or whitish appearance in black eyeball.    

Provide sun protection means child should not look at sun while playing in outdoors, this may damage internal eye (retina).

Your child's eyes should be examined regularly, particularly during infancy and childhood.

First aid tips for eye injuries:

• If your child spills something in his or her eye and you don't know what it is, or if there is a chemical (acid or alkaline) substances in it, flush your child's eye with water for at least 15-20 minutes and seek ophthalmic consultation at the earliest.
• If your child is hit in the eye with a blunt object, examine the eye closely. If you see bleeding or unable to open the eyelids, seek ophthalmic consultation at the earliest.
• If your child continues to be in pain, constantly rubs his or her injured eye, has persistent tearing, or complains of blurry or double vision - in the meantime, cover your child's injured eye with a cold pack for 5-10 minutes every hour or so.
• If your child's eye is injured with a sharp object, do NOT press on the eye or eyelid. Cover the eye with a shield (the cut-out bottom of a foam cup would do) and seek immediate ophthalmic consultation. If the sharp object is still in the child's eye DO NOT remove it. Instead cover the eye with eye cup or shield.

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