Driving at night – What should I know?

Courtesy of Johnathon, Flickr Creative Commons

Courtesy of Johnathon, Flickr Creative Commons

One of the most common questions patients ask is how to improve their night vision. In fact, many elderly patients have given up night driving all together.

So, what is it about night driving that makes it so hard? Well certainly, our visual abilities are dependent on light. With reduced lighting comes a variety of limiting factors like reduced visual acuity, poor color vision, decreased depth perception, and impaired peripheral vision. All of these factors combine to make accidents 3x more likely at night.

So, how do we reduce our chances of an accident?

1) It is imperative that your vision is corrected to its maximum potential. A complete eye examination will not only check the best prescription for you – it can also detect potential problems that affect night vision like dry eye, cataracts and macular degeneration, all of which occur with greater frequency with age. Additionally, if you are prescribed glasses at your visit, make sure to obtain lenses with an anti-reflective coating. This coating will reduce glare dramatically and has been shown to improve reaction time.

2) Make sure your windows and headlights are perfectly clean. Every time I clean my windows at a gas station I wonder why I didn’t do it earlier. This advice goes for your glasses too. Even a perfect prescription can be worthless if your glasses are dirty or scratched.

3) Finally, it is important to know your limits. If you have real concerns about night driving there is nothing wrong with asking for a ride, catching a cab or public transportation or just ordering in. Until next time, be safe on the road!

 ~Dr. David Ardaya, OD
California Optometric Association
http://eyehelp.org
http://www.coavision.org

What’s gradual, painless and dubbed the Silent Thief of Sight?

The answer is Glaucoma, an eye disease that slowly causes you to lose your vision.  If you’ve been proactive in monitoring your health, you should hopefully have a pretty good idea of certain health conditions that run in the family.  For example, mom has high cholesterol, dad has diabetes and you remember your grandmother uses eye drops for something.  Knowing your family eye history is very important because most eye diseases tend to be genetic.  Glaucoma, for example, tends to run on the mother’s side of the family.  If your mom has glaucoma, make sure you tell your optometrist.

glaucomadimming_55Laney69

Courtesy of 55Laney69 on Flickr
(Left – Normal Vision, Right – with glaucoma)

What exactly is Glaucoma?  It’s a disease where the optic nerve slowly deteriorates as a result of poor blood flow and is often accompanied by high intraocular pressures.  The optic nerve is a bundle of smaller nerve fibers, similar to a conduit, which transmits electrical signals from the retina to the brain.  In glaucoma, the smaller nerve fibers slowly deteriorate, resulting in a gradual loss of vision.  The first areas of vision loss will occur in the periphery, off to the sides, which is very difficult to detect since we are not often aware of our peripheral visual field.  If a patient experiences symptoms, the first symptom may be poor night vision.  As the disease progresses, vision loss creeps in toward the center of your visual field.  By the time you notice that you are losing your peripheral vision and developing “tunnel vision,” you will be in the late stages of glaucoma.

The good news is that glaucoma is the leading cause of PREVENTABLE blindness.  Routine eye examinations will allow an optometrist to detect glaucoma sooner.  There are a variety of tests necessary to detect glaucoma such as a visual field screening, measurement of the intraocular pressures, and careful evaluation of the optic nerve to detect changes.  Many offices now incorporate retinal photos into their routine examinations that are invaluable in detecting many retinal diseases including glaucoma.  Glaucoma is a diagnosis over time, it is rarely diagnosed on a first visit.  When change is detected in the structure of the optic nerve or in the thickness of its surrounding nerve layer over time, then glaucoma is diagnosed.  This is where comparing current retinal photos to older ones are helpful in detecting small changes over time.  Another important tool in the last few years is the Optical Coherence Tomography, which measures microscopic layers of the retina to detect microscopic changes.

So what happens if you do have glaucoma?  Treatment is often pretty simple.  There are a few different forms of glaucoma.  The majority of them are treated with eye drops with dosages as little as once a day.  The medicated eye drops lower the intraocular pressures in the eyes, which help to slow down the progression of glaucoma.  Some patients require laser treatments to lower their pressures.  Most cases of glaucoma are manageable and treatable if detected early.

I usually tell my patients that the ages of 20s and 30s is for establishing a baseline.  This is where routine examinations and photos are useful.  The ages of 40s and onward is for detecting change and eye diseases, and treating early.  Of course, as with any other diseases of the body, staying healthy is key.  Those with diabetes have a much higher likelihood of developing glaucoma so keep your blood sugar under control.  Those of Asian, Latino and African descent have a higher tendency for developing glaucoma.  Having a high amount of nearsightedness also puts you at greater risk.

The take home message is that glaucoma is treatable if detected early.  So know your family health history, stay healthy and see your optometrist routinely for comprehensive eye examinations.

~Cindy P. Wang, O.D., F.A.A.O.
California Optometric Association
http://www.coavision.org   
 

Vision and the aging eye

Courtesy of ORBIS US on Flickr

Courtesy of ORBIS US on Flickr

Many patients reach a certain life stage and realize they need to start thinking more about their vision and preventing eye problems.  This usually happens in their early to mid-forties when people notice reading is a lot easier when there’s plenty of light and the print is held further away.  Those who have seen an eye care provider for this problem should have already discovered that this is a normal aging process.  But how does one know when vision changes are normal or should be concerning?

Eye conditions that impact vision:

  • Presbyopia is the medical term for when the focusing muscles in the eye are not as flexible, causing poor focusing ability for objects nearby.  This typically occurs in the late thirties/early forties and is easily corrected with reading glasses or bifocal or progressive lenses.
  • Cataracts begin to develop in our forties and progress over time.  There is a natural clear crystalline lens in our eye which focuses light onto our retina.  With ultraviolet ray exposure, this lens can become more opaque and yellow over time, causing a dimming of vision and glare and haloes around lights.  The best way to prevent cataracts from progressing quickly is to protect the eyes with UV-blocking sunglasses anytime you are outdoors.  The good news about cataracts is that they can be easily removed and replaced with an artificial lens implant.  With the latest technology of intraocular lens implants such as muiltifocal lenses, patients are now able to see clearly at all distances without the use of glasses or reading glasses.
  • Glaucoma is a symptomless eye disease of the optic nerve head where the nerve slowly deteriorates over time.  Most patients who develop glaucoma will not have any symptoms until the late stages of the disease, when peripheral vision deteriorates and patients are left with tunnel vision.  There is no cure or preventative measure for glaucoma, however, it is easily treated with eyedrops.  The only way to determine if you have glaucoma is to have annual comprehensive eye examinations.

    Courtesy of Nargopolis on Flickr

    Courtesy of Nargopolis on Flickr

  • Macular Degeneration is another common eye disease that can cause debilitating vision loss.  This occurs when the macular region of the retina loses its integrity causing poor central vision with distortion or gray spots.  It is often detected upon routine examination, especially when photos of the retina are compared over time.  Fortunately, there have been extensive studies on macular degeneration and the field has changed dramatically over the last several years.  An important test in recent years is genetic testing to determine one’s risk factor for vision loss as a result of macular degeneration, as well as antioxidants that may be useful in reducing this risk.  Clear risk factors include a history of smoking, exposure to ultraviolet radiation, increased cholesterol levels and Caucasian women with lighter eyes and fairer complexions.
  • Retinal Detachment tends to occur more often in those who are older than 65.  The retina is a thin and fragile tissue that lines the back wall of the eye and sends visual information to the brain.  This tissue becomes more fragile over time and can easily develop a hole or tear leading to a retinal detachment.  If you experience flashes of light, new floaters, or a change in your vision, you need to be seen right away by your eyecare provider.

There are a myriad of eye conditions that can develop as one ages.  The most important and useful method of preventing vision loss is to stay healthy.  See your primary care physician regularly to evaluate and treat high blood pressure, high cholesterol, diabetes and other health conditions.  If you have uncontrolled health conditions, you can easily lose your vision to diabetic retinopathy, hypertensive retinopathy, or a stroke in the eye.

So, as I tell all my patients, see your physician regularly, eat green leafy vegetables, take your medications, and monitor your own blood pressure or blood sugar.  And of course, wear sunglasses outdoors and see your optometrist annually.

~Cindy P. Wang, OD, FAAO
California Optometric Association
http://www.coavision.org

The SCARY… and fun truth about colored contact lenses

Colored contact lenses are a popular topic this time of year as many people prepare their Halloween costumes. How fun is it to have a cool accessory like tiger eyes, cat eyes or red or white eyes to complement the most creative of costume? Colored contacts are a great fun option.  There are also many people who like to wear colored contact lenses daily to make their eyes more blue, more green, more brown or a different color all together!

Courtesy of therefromhere on Flickr

Courtesy of therefromhere on Flickr

However, most people do not realize that even contacts worn for cosmetic purposes still pose a potential health risk for the eye if not properly fitted. This is true even if there is no prescription on the lens.  Contact lenses are classified as “medical devices” with the FDA.  Regardless of a corrective prescription, contacts are plastic on the surface of the eye and need to be fit properly and be taken care of properly to lessen the chance of vision threatening infections such as corneal ulcers.

Doctors of optometry perform additional tests above and beyond the glasses and eye health examinations when fitting contacts. We evaluate the size and shape of the cornea, the health of the tear layer and the fitting relationship between the cornea (the outer surface of the eye where the lens sits) and the contacts lens to insure the safest most appropriate lens for each individual patient.  We also educate patients on the best cleaning and wearing regimen for the them.  This greatly reduces any complications associated with contact lens use.

Buying contact lenses without a doctor’s prescription is something that happens with colored contacts often.  This practice leads to rise in vision threatening conditions that could be prevented with a proper contact lens examination. So, buy a different kind Halloween contact lens for each Halloween party this season, but get a prescription first!

~Lisa Weiss, OD, MEd, FCOVDCalifornia Optometric Association
http://www.coavision.org

Night blindness 101

The term night blindness sounds alarming, as though some people are actually blind at night.  There is a small percentage of the population that does in fact experience true night blindness, but it is rare and often the result of late stage eye disease.  In optometry, it is not common to use the term night blindness although we do encounter a significant number of patients who complain of poor night vision.  The symptoms are usually blur and dimming of vision at night, glare and haloes around lights and poor adaptation from light to dark environments.  How do you know if what you are experiencing is normal or a result of something more serious?

There are a handful of eye conditions that can create symptoms of poor night vision.

Photo Courtesy of kenleewrites on Flickr

Photo Courtesy of kenleewrites on Flickr

  1.  Patients who have had surgery to the corneas such as LASIK or corneal transplants may notice glare and haloes around light.  They may also experience diminished contrast sensitivity which can cause images in the evening to appear more dim.  Unfortunately, surgical results usually cannot be reversed.
  2. Cataracts are the number one cause of decreased night vision.  Patients over the age of 40 will begin developing mild cataracts.  This is when the natural lens inside the eye becomes more yellow and opaque as a result of age and ultraviolet exposure.  Cataracts can cause haloes and dimming of vision in the dark and decreased contrast sensitivity.  Fortunately, cataracts are easily removed thereby restoring problems with night vision.
  3. Corneal diseases such as keratoconus and severe dry eyes may also affect one’s vision in the evenings causing double vision or haloes.  For some of these patients, specialty contact lenses or eyedrops will alleviate these symptoms.
  4. Newer technology has also allowed optometrists to detect higher order aberrations in some patients.  For these patients, standard spectacle lenses may not improve night vision problems.  An instrument to detect higher order aberrations will determine whether a patient requires a specialty custom-made spectacle lens to improve night vision.

Some patients do in fact have true night blindness caused by an eye disease in its late stage.  Usually, symptoms begin slowly over time and progress to an inability to see in the dark.  These patients usually suffer from one of two eye conditions.

  1.  Retinitis pigmentosa is an inherited eye disease of the retina, the tissue that lines the back wall of the eye and captures visual images.  Retinitis pigmentosa affects the rods of the retina and causes slow deterioration of these structures.  The rods (unlike the cones) are responsible for night vision and for peripheral vision.  As the disease progresses, patients will notice a decrease in their ability to see in the dark and in the periphery.  Unfortunately, there is no current cure for retinitis pigmentosa.
  2. Glaucoma is an eye disease where the optic nerve slowly degenerates.  Patients with glaucoma usually have no symptoms in the early stages of the disease.  As the disease progresses, nerve fibers in the retina begin to deteriorate resulting in a decrease in peripheral vision as well as night vision.  Usually, patients do not experience symptoms of poor night vision and poor peripheral vision until the late stages of the disease.

Now that you know the causes, what are some ways to alleviate or improve poor night vision?  The simplest solution is to wear an updated pair of prescription glasses (if you have a prescription) with higher index lenses and an anti-glare coat.  Your optometrist can also inform you if you require customized lenses to correct for higher-order aberrations.  If your night vision problems are not a result of surgery or any eye diseases that you are aware of, then it is important that you visit your optometrist for a comprehensive eye examination.

– Cindy P. Wang, O.D., F.A.A.O.
California Optometric Association
www.coavision.org

It’s just the FACTS: Vision & Learning Go Hand in Hand

August has been recognized as the Vision & Learning month.  It would seem appropriate since many children return to school in August or shortly thereafter.  In addition to getting new clothes and supplies for our kids, this yearly routine should spur us to take our children in for a comprehensive eye and vision examination.

Vision is a highly complex and intricate process.  So, it is not surprising that reading and learning is dependent on not only having excellent 20/20 vision, but also accurate eye movement, eye focusing, eye teaming, and visual motor skills.

It’s just the plain ole fact that there is a direct correlation between vision and learning.

Courtesy of woodleywonderworks on Flickr

Courtesy of woodleywonderworks on Flickr

Did you know that…

  • “25% of students in grades K-6 have visual problems that are serious enough to impede learning.” – American Public Health Association
  • Approximately “80% of children with a learning disability have an  undiagnosed vision problem.”– Vision Council of America
  • “1 in 4 children has an undiagnosed vision problem which can interfere with learning and lead to academic and/or behavioral problems.”  – College of Optometrists in Vision Development
  • Studies show that “children who had visual perceptual and eye movement difficulties did poorly on standardized tests.” – Dr. Lynn Hellerstein, FAAO, FCOVD, Past President of COVD
  • “When vision problems go undetected, children almost invariably have  trouble reading and doing their schoolwork.  They often a display fatigue, fidgeting and frustrations in the classroom – traits that can lead to a misdiagnosis of dyslexia or other learning disabilities.” – American Optometric Association
  • A “child with a vision based learning problem has excellent verbal skills, causing parent and educators to think the child must be lazy, have ADD/ADHD, or is learning disabled.”
    – College of Optometrists in Vision Development

A cursory vision screening is just not enough to detect vision-related learning difficulties.  Early prevention of a child’s vision problem is so important for school readiness, learning and academic success.  So make it an integral part of your child’s back-to-school preparations.  Buy school supplies, outfit your child with new clothes, and most important, take your child to see a doctor of optometry for a thorough eye and vision examination.

~Judy Tong, OD, FAAO

(Special thanks to my colleagues Drs. Carmen Barnhardt, Eric Borsting, Ray Chu, and Rebekah Louie.)

Quick Tips for Sports Vision

To do well in sports, you need to have your eyes working at the top of their game. Here are a few quick tips to help you or your athlete perform better:

  • Make sure you have a proper prescription on, whether it is contact lenses or glasses. Having your vision dialed in correctly is the most important step to get your eyes working their best.
  • Be sure to protect your eyes! Polycarbonate or other protective plastic lenses can keep your eyes protected while you play as well as keeping dust or wind from getting in your eyes while you play the sports you love. This table can help you determine which types of eye protection are best for the sport you play. (http://www.allaboutvision.com/sportsvision/eyewear.htm )

    Photo Courtesy of Morgan Burke on Flickr

    Photo Courtesy of Morgan Burke on Flickr

  • Consider color filters for your field of play. Certain types of filters or tints can increase your contrast sensitivity and thereby increase your reaction times. Allaboutvision.com has an excellent table for different tints to help in different sports (http://www.allaboutvision.com/sportsvision/lens-tints-chart.htm ). Remember, the faster you can recognize that curve ball, the easier it will be to adjust your swing!

~Ranjeet S. Bajwa, OD