Prescription Sunglasses: A Review of Transition Lenses

By: Anthony Tangeman

I’ve lived in Florida my entire life and I’ve spent plenty of time exposed to the sun. Whether it was for sports, marching band or yard work, I almost always had a pair of sunglasses with me.

I had never owned a quality pair of sunglasses. I had always used cheap sunglasses that you could find at your local dollar store.

These glasses worked just fine as they helped reduce the intensity of incoming sunlight. As my eyesight started to diminish I started needing a prescription. I could not wear those cheap sunglasses anymore.

Just recently I was presented with various kinds of prescription eyeglasses that would help combat the harsh Florida sun. I was asked to give them a test-drive and to share my experiences.


The first pair I tried out had polycarbonate lenses with gray transitions (VII).

transitions_clear

My transitions with clear lenses

Up until this point I had only heard about transition lenses. I didn’t know anyone who owned a pair. On paper the concept sounded nice: Exposure to UV rays would automatically darken the lenses. Once you went indoors, the lenses would gradually become clear again. It seemed nice and convenient needing to have only one pair of glasses.

The first time I tried on the glasses I found the transition from clear to dark to be seamless. It is a gradual process and thus difficult to notice while it’s happening, but the lenses do activate quickly. I was happy with the amount of protection the lenses offered against the harsh sunlight. It wasn’t the best sun protection I’ve experienced, but the tint helped ward off the sun. After going indoors the lenses eventually transitioned back to clear. At that point it was like wearing my every-day normal pair of glasses with clear lenses.

transitions_comparison

A comparison between clear and activated transitions

As I had imagined, the lenses were certainly convenient. I started referring to them as my “jack-of-all trades glasses” as you could wear them in any situation, whether indoors or outdoors.

Of course, a jack-of-all trades is a master of none, and there are a few drawbacks with these lenses. While these glasses did help protect me against the sun, I found myself wanting some more protection. My lenses were not polarized, so I had a problem with glare. If you are like me and live in a southern, sunny climate, you may want to look for a stronger, more dedicated pair of sunglasses with polarization.

The most notable thing to understand about transitions is that it takes considerably longer for the lenses to deactivate than to activate. This is a problem when going from intense sunlight to indoors. It is almost as if you were wearing sunglasses indoors. It can make things difficult to see, depending on how dark the lens tint is. However, I never found the activated lenses to hamper my vision so that I wanted to take the glasses off indoors. It is something to keep in mind when thinking about getting a pair of transitions.

That being said, I cannot stress enough that wearing the inactive glasses indoors felt just like wearing my normal pair of prescription eyeglasses. They feel nearly identical to my regular pair of glasses. It’s amazing to me that you get clear glasses with the added benefit of a little bit of tint to help out with the sun.

Overall I’d say that transitions are great for the person who values convenience and sun protection in that they allow you to get by without a dedicated second pair of sunglasses.

As I said earlier, I find that these transitions are my “jack-of-all trades glasses.” They will get me through the day no matter the situation. If you go into transition lenses with this mindset, you’ll be more than satisfied with your glasses.

We’ll be continuing our review series with another pair of sunglasses, so be sure to look out for it. Hope to see you then!

Eyewear Sun-Protection for Babies and Toddlers

By: Anthony Tangeman

If you spend time outside, it’s a good idea to invest in some form of sunglasses. This is true no matter your age, but this is especially true for babies and toddlers as they are helpless against the sun and its harsh light. If left unprotected, your child’s eyesight can become permanently damaged.

– If you would like to read about why UV protection is so important for babies and toddlers, follow the link to our blog here –

There’s no need to worry as there are plenty of options to consider. While this may seem daunting at first, choosing a pair of sunglasses for your child does not need to be difficult. The most important thing is to think of your child’s needs.

For example, a child that is only occasionally outside would likely benefit from having photochromic lenses, or lenses that adapt to incoming light. Photochromics are not only effective, but also convenient. The most popular photochromic lenses are transitions and drive-wear.

Transition lenses are normally clear, just like regular glasses. Once you go outside, UV rays from the sun activate the lenses and they start to darken. How dark and the color they become depends on your specific lens. The activation time on transition lenses is quite fast, which make them quite good for people who go from indoors to outdoors frequently.

Drive-wear is similar to transition lenses in that they become darker when exposed to light. However, there are quite a few differences to consider. Drive-wear by default has a slight tint to it, which makes them less suitable indoors. In addition, drive-wear lenses activate not only by UV rays but also by visible light. If your child has mild light sensitivity, drive-wear may be a good option since the lenses will usually be activated to some degree, offering relief from light.

In most cases I would personally recommend regular photochromic or transition lenses. From my experience transition lenses when not activated are just like regular, clear lenses. When activated they provide decent protection from the sun. Unlike drive-wear, transitions are perfect for indoors. Whether you go with transitions or drive-wear, your child will only have to wear one pair of glasses whether they are outdoors or indoors, which can be very convenient.

On the other hand, your child might spend a great deal of time outside. Perhaps your family lives in a sunny area, or maybe your child plays sports outside. They would greatly benefit from having a dedicated pair of sunglasses.

In this case I would highly recommend looking into polarized lenses with amber blue-blockers. Polarization is great for blocking glare, especially when looking at long horizontal surfaces such as roads, fields, or water. The amber blue-blockers describe the tint to the lens, which as the name suggests blocks blue light. These lenses increase contrast which can be quite helpful for sports or other activities that require hand-eye coordination. Other effects include more natural looking colors, and a more comfortable viewing experience while outdoors.

For most people I highly recommend having a pair of glasses for indoors and one for outdoors. Consider using transitions as the indoor glasses as they just as fine indoors compared to regular glasses but also offer sun protection while outside. Also, while not covered in this blog post, look into different tints for sunglasses and see what would be best for your child. Different color tints are more useful in certain situations.

In short, it’s all about providing the best protection for your child. The best way to do that is to consider what would benefit your child the most. If you need help figuring this out, ask your local optometrist for their opinion, or even ask us! We’re more than happy to help point you in the right direction. As always, thank you for reading!

Children and Strabismus

By: Anthony Tangeman

Strabismus, also known as crossed eyes or wandering eyes, is a vision condition caused by a muscular imbalance in the eyes. This imbalance prevents both eyes from aligning properly in order to focus on an object. One eye, and sometimes both eyes, will turn away in some direction from the object. In the case where one eye turns away (unilateral strabismus,) one eye becomes dominant over the other. There are different types and degrees of strabismus. We will be focusing on what unilateral strabismus is, how to look for it, and the treatment options for it.

As with any eye condition concerning babies and toddlers, early detection leads to the most successful treatment. Babies should have their first comprehensive eye exam at six months of age. It is then recommended for children to have exams again around the ages of three and six, and then once every year or two depending on your child’s vision.

While professional optometrists and ophthalmologists can easily spot and test for strabismus, it may be possible for you or other people to find signs and symptoms of strabismus in your child. One of the good things about strabismus compared to other vision conditions is that it is often very noticeable, and thus relatively easy to detect. Depending on the degree of strabismus, you might simply notice that your child’s eyes are not aligning properly. However, be aware that for very young children (from birth to three or four months) the eyes are still developing and misalignment might not necessarily mean that they have strabismus.

For babies older than four months, there are a couple signs you can look for. If your baby often tilts their head, it may mean that they are having trouble focusing on what they are trying to look at. Similarly, frequent squinting may also mean that they can not properly focus their eyes. Both signs could lead to a possible diagnosis of strabismus.

For children that can talk and communicate, a common complaint is that they will see double. This double-vision is caused by misaligned eyes. The brain ends up receiving two different images of the same object. Be aware that double-vision may disappear over time as the brain will learn to cope with the eyes. However, overall vision will be reduced and your child will still have strabismus.

Detection and treatment for strabismus is so important because if left unattended, your child can have lasting vision problems. Strabismus is one of the causes of amblyopia, which can be thought of as a more severe version of strabismus. Essentially, instead of there being a dominant and weak eye with strabismus, amblyopia has a dominant eye and a turned-off eye. Due to the muscular imbalance in strabismus, the weaker eye ends up having a weaker connection to the brain. Over time, this connection dwindles until the eye is eventually turned off. Amblyopia caused by strabismus is known as strabismic amblyopia.

It is important to note that strabismus is not synonymous with “lazy eye,” which is another word for amblyopia. Strabismus can be a cause of amblyopia, but not the other way around. The point where strabismus becomes amblyopia is when the brain completely disregards the weaker eye. It is important to make this distinction as potential treatment options change depending on whether your child has strabismus has strabismic amblyopia.

Amblyopia always needs to be addressed first and must precede any surgery that might occur. For more information on amblyopia and its treatment options, go here.

For strabismus, there are a couple of treatment options. The first is vision therapy, where the focus is on training and improving vision without the use of surgery. Through therapy, the eye muscles are strengthened, in turn fixing eye alignment. In addition, the connection between the eyes and brain increase, improving motor skills and the ability for the eyes to focus. Therapy is done through the use of optical devices, including lenses and prisms. Optometrists often will have patients come into their office for therapy, as well as having patients do additional therapy at home.

The second option is surgery. Surgery for strabismus is a procedure that connects the eye muscles and the eye itself. Depending on your child, they may need a weaker connection (recession) or a stronger connection (resection). In both cases, the eye muscles are stitched to the eye. The sutures can either be permanent or adjustable. In general, adjustable sutures are only advised for people at or beyond the age of young adult, or simply for people who are willing to cooperate with the procedure.

It is important to monitor your child following surgery as there are some effects to be aware of. Your child will likely have red, swollen eyes. The eyes might also be sore, in addition to giving off mucous. These conditions normally disappear over time. However, it is possible that double-vision can still exist post-surgery. If that happens, or if the redness and swelling persist or worsens, be sure to see the doctor as soon as possible.

In general, be sure to communicate with your child’s doctor in order to determine what to look out for, what your child can and cannot do immediately after surgery, and when to schedule follow-up appointments.

The key with strabismus, and other vision conditions, is to be proactive. Early detection and treatment give your child the best opportunity to grow and develop normally. Always be on the lookout for signs of vision problems, and be sure to schedule an eye exam if you think anything is wrong.

As always, feel free to contact the professionals at GoSmartEyewear for all of your vision related questions and concerns.

Children and Amblyopia

By: Anthony Tangeman

Amblyopia, or “lazy eye,” is a common vision condition. Among children, it is more common than every other child vision problem combined and sometimes can be difficult to see. If left undetected and unattended it may cause permanent loss of vision. Because of this, it is important to understand what amblyopia is, what it does, and how it can be corrected.

A person has amblyopia when there is a problem with the eyes that causes one to be dominant over the other. The brain will favor the dominant eye, either learning to cope with one eye or even turning off the weaker eye. In both cases quality of vision is greatly reduced. Amblyopia is almost always unilateral, meaning that it affects one eye, but it can also be bilateral. There are different types of amblyopia depending on what type of problem the eyes have. They are as follows:

Strabismic amblyopia – Occurs when the orientation of the eyes are not correct. Both eyes become unable to focus on the same object. The brain senses this and turns off the problematic eye, meaning that the brain ignores any visual input that would be sent out. Strabismic amblyopia is relatively easy to spot in children compared to the other forms of amblyopia.

Deprivation amblyopia – Occurs when a child has a vision condition, such as cataracts, which impairs vision in one eye. The brain will adapt and learn to see the world with cloudy vision. This is problematic as corrective prescription eyeglasses will not improve vision as the brain has become accustomed to seeing blurry images.

Refractive amblyopia – Occurs when there is a significant difference in the quality of vision between the eyes. Similar to strabismic amblyopia, the brain will shut off the weaker eye, causing a loss in vision.

The best defense against amblyopia is early awareness and treatment. The sooner you know your child has amblyopia, the better chances you have at protecting their vision. Deprivation and refractive amblyopia are much more difficult to see in children. Something that you can try to test for these types of amblyopia are to cover one of your child’s eyes at a time and to see how they react. If they show signs of discomfort when you do this, it is possible they have amblyopia.

Treatment varies slightly across all types of amblyopia. In general, your child will be prescribed a patch to wear over the dominant eye. This gives the weaker eye the opportunity to grow stronger. Strabismic and deprivation amblyopia additionally require surgery after eye-patching in order to fix eye orientation or other vision conditions respectively.

Sometimes eye drops will be prescribed instead of an eye patch to treat amblyopia. These are usually atropine drops which dilate the eye. The purpose is the same as the patch, to allow the weaker eye to grow stronger. The eye drops essentially cause blurry vision in the eye they are applied to. It is important to note that these eye drops come with possible side effects, including itching, burning, and stinging of the eye. It is important to monitor your children if they are being prescribed atropine drops.

When you suspect that your child has amblyopia, you should have their eyes examined as soon as possible. It is recommended that children have their first eye examination at the age of 6 months. Most of them have regularly scheduled eye exams around 6 years of age. As a parent it is crucial to ensure that your child has the healthiest vision they can. Always be on the lookout for signs of vision problems, and be sure to seek help and advice if you have any concerns.

Please contact GoSmartEyewear if you have any questions about your child’s vision.

Children and Anti-Reflective Coating

By: Anthony Tangeman

In our last post we described the science of anti-reflective (AR) coating, going into detail on exactly how it works. We know that the coating reduces glare caused by light reflected off the lens, but you may be asking yourself, “Does my child really need AR coating? Is it worth the price?”

As parents and guardians, we must remember that vision is a key factor in a child’s emotional and intellectual development, especially while they are infants. People grow and learn skills over time. As babies, we listen to our parents talk and we try making those same noises. We see them walking around and we clumsily balance on our own feet. In a similar manner, we train our eyes in order to see the world around us. This “training” happens soon after birth, with the largest developments in our vision occurring over the first two years.

Whether or not your child needs to have AR coating largely rests on your child’s eyeglass prescription. If your child has polycarbonate or high-index lenses, you should seriously consider AR coating. These lenses reflect more light, which can be counter-acted by the AR coating’s ability to absorb light and reduce glare. Because of this, your child would greatly benefit from improved vision and increased comfort.

But what if your child does not have polycarbonate or high-index lenses? Would they still need AR coating? Not necessarily, but I would still definitely recommend it. Regardless of how much your child needs AR coating, one thing is clear: AR coating reduces eye strain, promotes healthy vision over time, and offers aesthetic benefits to your child’s glasses.

When glare exists on the lens it can be difficult to actually see the eyes of the person wearing the glasses. AR coating eliminates glare, meaning that people can see your child’s eyes clearly through the lens, whether in person or in pictures. Younger children can become discouraged if they suspect people have trouble seeing them clearly. Your child can be confident and comfortable knowing that other people can see their eyes without trouble.

In essence, AR coating allows for a more positive experience in wearing eyeglasses. Your children should want to wear their glasses. They should feel comfortable wearing their glasses. The vision and aesthetic improvements AR coating provides helps facilitate a positive experience with prescription eyeglasses. Thus, AR coating is well worth it and should seriously be considered for anyone wearing prescription eyeglasses.

As always, please contact GoSmartEyewear for any questions regarding prescription eyeglasses and vision.

The Science Behind Anti-Reflective Coating

By: Anthony Tangeman

Anti-reflective (AR) coating is an option to consider adding to your eyeglass lenses. The coating greatly reduces glare caused by light reflected off the lens. Because of this, AR coating both improves vision through the lens and allows others to see your eyes more easily through a clear, glare-free lens.

AR coating works by altering the light that passes through the lens. To understand exactly what the coating does and how it works, we must first understand waves.

sine_wave

Basic elements of a wave

Light waves, such as the one above, are most easily represented as having a sinusoidal shape. Sine waves have cycles that repeat continuously. The time (t) it takes to go through one cycle is the period. The distance between two reoccurring points in a wave is the wavelength. Wavelength is often measured between two crests (high point of the wave) or two troughs (lowest point of the wave). The amplitude (E) describes the strength of the electromagnetic field at a particular point along the wave.

Related to and described in terms of wavelength is phase. Phase is, at any point in a wave cycle, the fraction of the total wavelength that has elapsed. When comparing two identical waves we can describe a phase shift, or the difference in phase, between the two waves. When there is a difference in phase, the waves are said to be out of phase. On a graph, this simply looks like one wave is shifted horizontally to the side of the other. When there is no difference in phase, waves are said to be in phase. Below is an example of two identical waves that are one-quarter wavelength out of phase.

phase_shift

Visually, the wave is simply shifted to the left

The key to AR coating is phase and interference.

constructive_interference

Resultant wave has twice the amplitude of the original waves

Think of two waves traveling towards each other through the same medium. Both waves are identical. In our diagram above, the waves are in phase and meet at their crests. As a result, constructive interference occurs. The amplitude observed from these two colliding waves sees a positive net change, or in this case is twice the original amplitude.

destructive_interference

Both waves cancel each other out completely

Depending on phase, two colliding waves of the same wavelength will produce a resultant wave that is either enhanced or diminished. AR coating utilizes phase to cause destructive interference. Light entering through the lens will encounter itself, now reflected and experiencing a phase shift due to the coating. The two waves, now out of phase, collide and effectively cancel each other out, eliminating any glare that would normally exist. It is in this way that AR coating both improves vision through the lens and makes it easier for others to see your eyes through the lens.

So, we have now gone through the general science of how AR coating works. For our next post, we will examine the benefits of AR coating as it pertains to everyone who wears glasses, but especially how it is crucial for babies and children with eyeglasses.

For further information on the mathematics and physics behind AR coating, visit HyperPhysics.

For more information on wave interference, visit the Physics Classroom.

As always, feel free to contact GoSmartEyewear if you have any questions or concerns.

UV Protection for Toddlers

By: Anthony Tangeman

Whether you spend the day outside or you stay indoors, you are being exposed to ultraviolet (UV) rays. Sunlight and UV radiation are a part of everyday life. Although people tend to know that these rays are harmful, they often overlook this and later regret it. In addition to proper clothing and topical solutions, such as sunscreen, a pair of eyeglasses with UV protective lenses is an essential element for proper UV protection.

The sun’s harmful rays have both short-term and long-term effects on our skin cells. Short-term effects, which tend to be visible, include tanning, sunburn, and rashes. A sunburn may be easy to spot and feel, but many people forget to consider the more dangerous, long-term effects caused by UV radiation.

Among skin aging, damage to the immune system, and skin cancer, eye damage is a concern that comes along with long-term UV exposure. UV radiation can damage the eye’s surface tissues, as well as its internal structures. Specific eye conditions that UV rays can cause include, but are not limited to: cataracts, non-cancerous and cancerous growths, and macular degeneration. Because of this, UV protection should be sought out as soon as possible.

Babies are more susceptible to UV radiation than adults. Not only do our bodies go through physical changes that prevent more UV radiation from penetrating us, such as the thickening of our epidermis, but we simply become more capable of fending for ourselves in general.

For instance, think of a toddler, sitting in a stroller and being pushed around by their parent during a bright, sunny day. The parent might not notice, but their child very well could be receiving the full force of the sun. Adults, and even older children, may have temporary solutions against the sun, some as simple as blocking out the rays by covering their faces of turning away from the sun. However, younger children can not do this. They are defenceless against the sun. They are simply helpless against it and will take the brunt of the UV rays unless they have proper protection. Because of this, it is critical to invest in UV protective eyewear for your children, particularly your babies and toddlers.

When seeking protection for either yourself or your child, it is important to understand that UV radiation is broken down into three subtypes: UVA, UVB, and UVC waves. It should be noted that UVC waves, with their shorter wavelengths, are completely absorbed by the Earth’s ozone layer. Because of this, we only need to be concerned with UVA and UVB waves.

The material used in your eyeglass lenses or UV coating/dye is what determines your UV protection. Below is a table showing inherent UV protection for various lens materials.

uv_protection_in_lens_materials

GoSmartEyewear specializes in protective eyewear for babies and toddlers. Be sure to consider UV protection when ordering your eyeglasses. Care should be taken as soon as possible to protect your child’s eyes, and even your own eyes, from harm. If you have any questions or concerns about UV protection or any other eyecare needs, please feel free to contact GoSmartEyewear.

What Is Pupillary Distance?

By: Anthony Tangeman

In a previous blog post Michael Walach described how to measure Pupillary Distance, or PD. Now we are here to tell you exactly what P.D. is and why it is important.

You can likely infer what PD means from its name: it is the distance between the centers of the pupils in millimeters. While a simple concept, this measurement is crucial in order to have glasses perfectly suited for your eyes.

The purpose of measuring PD is to place the optical center of the lens directly in front of your pupil. The optical center is a point where light rays go through a lens without any deviation. Proper placement of the optical centers allows both of your eyes to focus easily without any strain.

Because of this, an inaccurate PD measurement can throw off an entire eyeglasses prescription. The good news is that the measurement is not difficult to take. If you have questions about taking the measurement, please see the above link to Michael’s article on measuring PD.

It is also important to note that PD may be written with two or four numbers numbers instead of one. This can mean that your measurement is displayed as monocular PD (one number for each eye), or near and distance PD (two numbers if binocular PD, four numbers if monocular).

Binocular PD is a single measurement between the centers of the eye pupils in millimeters. Monocular measurement is essentially PD measured from the center of the bridge of the nose to the center of the pupil. Monocular measurement allows a more fine-tuned placement of the optical center in each eye.

binocular_pd_ranges

PD is the starting point towards a proper eyeglasses prescription. When measuring your own PD, make sure to be as accurate as possible. The optical center, when positioned correctly, allows eyes to focus and see the world clearly without strain. For questions about PD or anything else eye-care related, feel free to contact GoSmartEyewear.

What Is Astigmatism?

By: Anthony Tangeman

Many people are frightened when their optician tells them they have astigmatism. While astigmatism is a fairly common vision condition, people often do not know what it actually is.

Astigmatism is one of the causes of blurry vision that occurs due to unequal curvature of the eye. Essentially, an eye with astigmatism is less perfectly round than one without it. An easy way to picture this condition is to imagine a baseball or basketball, both of which are perfectly round. Now picture an American football, which is egg-shaped. This egg shape is similar to an eye with astigmatism, except to a much lesser degree.

normal_and_astigmatic_eye_comparison

Image Credit: perfectvisiontherapy.com

In an eye without astigmatism, light passes through the cornea and focuses on a single point on the retina. However, due to the unequal curvature of the eye, an eye with astigmatism will have multiple focal points either in front of or behind the retina. This causes blurry vision.

It is important to note that astigmatism can occur early on in a person’s life. Because of this, be sure to regularly schedule an eye exam for your children.

The good news is that prescription lenses can remedy astigmatism, as well as other vision conditions. The opticians at GoSmartEyewear work to produce lenses that will address any or all correctable vision conditions you may have.

As always, please contact GoSmartEyewear if you have any questions or concerns.

How Do I Read My Child’s Eyeglasses Prescription?

By: Anthony Tangeman

Parents concerned about their child’s eyesight often want to have a better understanding of their child’s eyeglasses prescription.. By learning how to read a prescription, parents can better understand their child’s vision. Understanding a prescription comes down to learning the layout of a prescription and the meaning of each number and character.

Whether a baby, child, or adult, a person’s prescription will have the same general format.

simple_eyeglasses_prescription

Prescriptions have two rows labeled O.D. and O.S. These are abbreviations for Latin terms that mean right eye and left eye respectively.

From left to right on the top row of the prescription you will always find SPH, CYL, and AXIS. It is important to note that there may not be a value entered for these categories, meaning there is no correction needed.

SPH stands for spherical power and describes the degree of nearsightedness or farsightedness. A positive value, or one with a plus-sign, means that your child is farsighted, while a negative value means they are nearsighted. CYL is short for cylinder power, while AXIS simply means axis. Both of these terms describe astigmatism, which is a scary-sounding word for a very common condition. It simply means that the front of the eye has less of a perfectly round shape. The Cylinder value shows the severity of astigmatism, while axis measures the orientation of astigmatism.

To learn more about astigmatism, be on the lookout for our next blog post.

Depending on where the prescription came from there may be additional elements to your child’s prescription.

complex_eyeglasses_prescription

To the right of AXIS you may find ADD, PRISM, and P.D. ADD stands for addition and is used with multifocal lenses. ADD is additional magnification which helps with vision at close range. PRISM is used to help people with muscular imbalance in their eyes. P.D., or pupillary distance, is the distance between the centers of the pupils, which is used to position the lenses in frames.

If you would like more information on measuring P.D., please view our blog post on it.

While intimidating at first, eyeglasses prescriptions can be understood as long as you learn the layout and the meaning of the characters and numbers. If you have any questions regarding your child’s prescription, or anything else related to prescription lenses and frames, please contact customer service at GoSmartEyewear.