All You Need To Know About Progressive Lenses

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Progressive Addition Lenses (PAL) are multifocal lenses (glasses)

They’re used to correct focusing disorders that occur in most people after the age of 40 (presbyopia). These lenses may also be used for younger people that have disorders of accommodation, or for those individuals who have demanding near visual needs beyond the eye’s normal focusing capability. In this particular lens, distance vision is accessible through the top or “straight ahead” portion of the lens. Intermediate vision is viewable through the middle part of the lens, and reading/close vision is viewable through the bottom part of the lens. Unlike a lined bifocal or trifocal, the lens changes power in a gradient fashion from the top to the bottom of the lens – so no demarcation lines segment or obscure the lens, making this the top choice for the ability to multi-task between different visual distances and cosmetic appearance.

However, not all progressive lenses are equal! Many people have tried (and failed to adapt to) older style/conventional/basic tier lens designs that constrict the field of view to a very narrow corridor of vision, causing a very large distortion area to the immediate right and left of straight ahead gaze. These types of conventional progressives, utilize four- decades-old technology (often from the 1980’s) and are basically “semi-finished” manufactured lens blanks.  They cannot be customized and are being phased out by most manufacturers due to poor wearer experience and the inability to meet modern visual demands.  A wearer is expected to have narrow fields of vision, and is required to move/tilt their head significantly to find the ‘sweet spot’ in the lens.  An adjustment period of up to three weeks is typical, if a person is able to adjust at all. If you or someone you know has had a bad experience with progressives in the past – chances are, this is the type of lens that gave you that bad experience (there are many retail establishments that still offer this type of product due to the low cost of manufacturing them since they are not customized at all).

In the past, there weren’t many progressive design choices available so progressive wearers had to “put up with” the limited technology that was available at the time.

However, the visual experience with progressives has changed a lot over the last few years as newer technology and newer customized lenses designs have enhanced the choices to the point where this is now the primary lens of choice for people with differing focusing needs.

Newer progressives, such as the Shamir Autograph Intelligence, now feature a specific area to see your cell phone and also have a wider field of vision for the computer to better accommodate today’s wearers.  These higher quality progressives will have wider areas of vision (to the left and right of straight ahead gaze) that provide more usable vision in the lens.  In contrast, lower quality progressives will have a narrower field of vision and have more peripheral distortion throughout the lens.  The quality level of a progressive lens can be defined by the terms “Conventional” (see above), “Digital”, and “Free Form”.

Digital progressives have become more common due to the ease of manufacturing them.  The term “digital” means that the tools used to manufacture the lens were computerized, which provide enhanced clarity to a lens – but not necessarily a wider field of vision.  Digital progressives are semi-molded and then finished at a later point with the wearer’s prescription.  While these lenses are clearer than conventional progressives, they are still limited by their semi-molded designs.  If “digital” is the only enhancement to the lens, it may be more clear facing forward but still have significant side distortion that makes the wearer feel “sea sick”, similar to a conventional (basic) progressive lens. Many retail establishments will incorrectly market these as the “highest quality” of progressives – but digital surfacing by itself only produces a mediocre lens at best. (Free Form progressives are the highest quality lenses available.)  An adjustment period of two to three weeks is typical with digitally enhanced lenses.

Free Form progressives, such as the Shamir Autograph Intelligence, are the highest quality lenses for an enhanced visual experience.

These are completely customized prescription lenses, and do not start out with pre-made lens blanks.  Similar to digital progressives, they are made using computerized tools, *but* they are not limited by semi-finished/molded designs – they are completely customized from start to finish. True Free Form lenses will be branded lenses from reputable optical technology leaders, and utilize patented technology from years of research and user feedback.  This patented lens technology cannot be duplicated or simulated by any generic or private label lens. Be skeptical of retail establishments that offer ‘Free Form’ with no specific brand name such as Shamir Autograph Intelligence, as these may just be standard/conventional digital progressives.  Free Form progressives are made uniquely based on several parameters: your individual glasses prescription, the measurements/shape of your specific frame of choice, and custom measurements of how that particular frame sits on your face.  The Shamir Autograph Intelligence progressive offers the widest and clearest area of distortion-free vision in a progressive and provides the easiest adjustment period.  Most new wearers immediately adjust to their prescription within just a few days and is the #1 choice of all our patients in terms of enhanced wearer experience and visual quality.

Preventing Computer Vision Syndrome

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What Is Blue Light/Computer Vision Syndrome?

Digital eye strain, also known as “Computer Vision Syndrome”, is a relatively unknown vision-related problem that many people suffer from due to prolonged computer, iPad, e-reader, and cellphone screen time. The eyes are most comfortable focusing on distance objects (10-20 ft away or more). When the eyes are forced to focus for long periods of time at much closer distances (typically 16-24 inches) on computer screens or any printed material, the eye muscles that control focusing get fatigued and strained – similar to how any other muscle in our body can get strained from over-use. Digital eye strain symptoms can include: blurry vision, double vision, eyestrain, headaches, difficulty concentrating or focusing, red/sore/tired eyes, and dry eyes.

Additionally, most computer screens, tablets, and cell phones emit blue light. Blue light is a very high energy wavelength of light, similar to UV radiation. While we get most of our UV and blue light from the sun, significant indoor sources of man-made blue light include fluorescent/LED lighting, computer screens, cellphones, iPads, flat screen TVs, and other digital devices. In the modern world, the average person tends to spend a large amount of time on these indoor devices, often in close proximity to a person’s face – because of this, many health care professionals are concerned about the possible long-term effects of blue light on eye health. Prolonged exposure to blue light has been shown to damage the retina, the crystalline lens inside the eye, and other ocular tissues – this exposure can contribute to the development of cataracts and age-related macular degeneration.

How To minimize the symptoms of Computer Vision Syndrome and Blue Light Exposure:

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Get a yearly eye exam and follow your doctor’s advice on prescription lenses.

Many people have mild vision problems that do not require everyday correction with glasses for driving, reading, or other activities – but can benefit from computer vision glasses to reduce visual stress at work from prolonged focus on the computer.

Make sure you let your eye doctor know the visual demands of your job.

Glasses for distance, reading, or both may not provide the appropriate focus for a computer screen, which is often 20-30 inches from your eyes. Measure the distance between your computer screen and your eyes, and let your eye doctor know what tasks you need to perform visually at work. This information will help your doctor work with you to come up with the best solution for your work-related visual needs.

Minimize blue light exposure and glare coming off your computer screen.

Blue light from monitors, tablets, and mobile devices can negatively affect your vision over the long term. Ask your doctor about specialty lens coatings that can reduce the harmful impact of blue light and disabling glare off the surface of your lenses and computer – both blue light and glare can contribute to eyestrain and computer vision syndrome. Consider a glare reduction filter for your computer screen, along with positioning your monitor so that it does not catch reflections from windows/artificial lighting/etc. Some devices have display settings that can be adjusted to reduce blue light.

Ensure the proper ergonomic set up for your work space.

When on the computer, do not set your monitor too high so that you are staring straight into the middle of the screen – this is a common mistake. Ergonomically, it is best to have your computer monitor positioned at least 24 inches away from you, viewing the screen in a natural neck posture with a slightly downward gaze.

Take rest breaks from near focus at regular intervals.

Remember the “20/20 Rule”: Every 20 minutes, take a 20 second break from the computer/near focus and adjust your gaze to a distance object at least 20 feet away (or more).

Minimize dry eye from prolonged screen focus.

When the eyes focus for long periods of time, our blink rate has a tendency to slow down. Consequently, as we stare at the screen all day, the surface tissue of the eye will dry out. Take care to blink full complete blinks so that the eyelid completely spreads your tear film from the top to bottom of your eye surface. Use artificial tears or lubricant eye drops (do *not* use redness relieving eye drops) every 1 hour to supplement the tear film. Avoid wind/fans/vents blowing directly into the face which will also dry out the eyes.

Specialty Contact Lenses for Keratoconus & Irregular Corneas: RGPs, Hybrid Contacts, Scleral Lenses

TopographerA computerized corneal topographer is a special non-invasive instrument used to diagnose certain diseases of the cornea and ocular surface. The cornea is the front anatomical structure of the eye and the first layer of the eye responsible for focusing light and vision. Some corneal diseases, such as keratoconus, pellucid marginal corneal degeneration, etc., are sometimes not easily detected by gross examination, but rather require topographical imaging, which scans and maps out the curvature of the cornea. This helps your optometrist confirm or rule out the diagnosis of these corneal conditions.

Once diagnosed with the appropriate corneal disease, your eye doctor can determine the ideal options to give you the best quality vision. With these certain conditions, the corneal surface is irregular. Thus, patients experience distortion, double vision, glare, haloes, and blur with soft contact lenses and glasses because light can no longer focus properly through the eye. Specialty contact lenses maintain their rigid shape as they curve over the cornea and ocular surface. Thus, the specialty contact lens resembles regular, rounded surface to provide better optics and vision; they include rigid gas permeable contacts, hybrid contacts, and scleral contacts.

The most common corneal disease to be fit with specialty contact lenses is keratoconus. Keratoconus is a progressive disease of the cornea, where the cornea becomes thinner with time due to a weakening of collagen fibers. As keratoconus progresses, the cornea begins to bulge outward and takes on a more cone shape. The age of diagnosis can range from approximately 10-30 years old. In mild cases, soft contact lenses and glasses can still deliver good vision, but as the disease progresses, specialty contact lenses are the best option.

At Grand Vision Optometry, we offer multiple choices of specialty contact lenses to suit your unique corneal needs:

  • Rigid gas permeable contact lenses (RGPs) are small lenses that rest on the cornea. They provide clearer vision than glasses and soft contact lenses. Under certain circumstances, RGPs may move around or dislodge due to their size.
  • Hybrid contact lenses are a bit larger in diameter due to their design that rests on the cornea. They have a soft peripheral lens edge and rigid center to combine better vision and comfort to resemble the comfort of a soft contact lens and superior vision of an RGP.
  • Scleral contact lenses are another comfortable larger diameter contact lens that acts a prosthetic to completely arch over the cornea, which act to mimic a normal ocular surface especially for patients with advanced keratoconus. They are less likely to dislodge from the eye and have better stability.

-Dr. Iris Wong

How to clean your glasses


Tips to Keeping Your Lenses Clean:

  • Do not use alcohol or ammonia based products on your lenses, as these can damage the special coatings on your lens.
  • When cleaning your lenses use an anti-glare safe lens cleaner that is not alcohol based.
  • Paper towels, Kleenex, and your shirt should be avoided as the fibers can be abrasive which may scratch your lenses.
  • Use a clean micro fiber cloth to clean your lenses, as a dirty microfiber cloth can end up just spreading around the oils and dirt (your lenses will look foggy).
  • To clean your microfiber cloth you can hand wash it with some gentle soap or throw it in with your next load of laundry.
  • You should wash your lenses once a week by applying a small drop of mild dish soap to each lens while rinsing under warm water.
  • For daily cleaning, apply a small amount of lens cleaner on each side of both lenses, then use your clean microfiber cloth to wick away any dirt and oils.

UNDERSTANDING SPRINGTIME EYE ALLERGIES

It’s getting to be that time of year again – when most allergy sufferers find their seasonal allergies kicking into full swing. The reason why springtime allergies hit us so hard in San Diego is the timing of plant reproduction cycles – it’s when the most pollen is in the air. Wind pollinated trees (such as oak and pine) tend to release their pollens between February and May and wind pollinated grasses release their pollens between March and October. At the end of May, ragweed and other weed plants are active, producing copious amounts of pollen – keeping allergy sufferers in agony until the end of autumn. Because wind-pollinated species of plants produce the highest volume of pollen, April and May tend to be peak allergy months.

Eye allergies, also known as “allergic conjunctivitis,” tend to be chronic, and flare up during periods of heavy pollen, dust, and other allergen exposure. Common allergic conjunctivitis symptoms are: itchiness, watery eyes/tearing, redness, swelling of the eye tissues and eye area, and eye irritation. These symptoms can cause significant discomfort, blur vision, and cause problems with contact lens wear.

To minimize the impact of eye allergies:

  • Do not touch or rub the eyes.
  • Wash hands frequently with soap.
  • Wash bed linens/pillowcases in hot water.
  • Reduce contact lens wear time or consider switching to daily disposable contact lenses.
  • Wash hair at night to prevent pollen from lodging in your pillows/blankets (allergens can get trapped in hair during the day, causing morning symptoms).
  • See your eye doctor for prescription strength eye drops and other recommendations that can reduce (and sometimes prevent) the allergic response.

Grand Vision Optometry uses the most advanced technology to ensure superior vision health diagnostic and treatment excellence. Additionally, because we believe in compassionate eye care, we will take every measure to provide your vision and eye health care in a pleasant, soothing atmosphere.

-Dr. Mika Fu