Archive for the ‘Eye Facts’ Category
Like humans, dogs can suffer eyesight problems and need good vision care. The difference between you and your dog, however, is that he is completely dependent on you for eye health protection and care. He also relies on you to identify any signs of vision loss and to get him to the vet right away. Here are some tips for protecting your dog’s eyesight:
- Don’t let your dog hang her head outside your car window while you are driving. While your dog may enjoy the ride, her eyes are vulnerable to injury while you are in motion.
- According to an article in NewsOK, it’s not a good idea to use old eye medications to treat an eye condition that has just cropped up. Talk to your vet each time your dog has an eye condition and use the medications that your vet prescribes.
- If you notice that your dog’s eyes are red, teary or that your dog is frequently rubbing his eyes, contact your vet right away.
- The ASCPA urges dog owners to keep an eye out for signs of vision loss in their dogs. Getting prompt veterinary attention is crucial for protecting your dog’s eyesight and preventing unnecessary pain and suffering. Typical signs of vision loss in dogs include unusual clumsiness, falling, and becoming easily startled. Your dog may also appear to lose confidence and be reluctant to move from place to place in your home.
Getting Help & Finding Resources
If you don’t have a vet, ask your friends for a referral, or check out review sites like Yelp. If your dog does have a serious vision problem, your vet may refer you to a veterinary ophthalmologist, a veterinarian who specializes in treating the eye. The American College of Veterinary Ophthalmologists can assist with referrals as well. In addition, its website contains a wealth of information on pet eye health issues.
Just as many of us humans ignore eye problems until we have difficulty seeing or experience a serious medical condition, it’s easy to ignore the signs of vision and eye health issues in your pet. Take the time to observe your pet’s behavior throughout the day so you’ll have an easier time identifying changes that may suggest vision problems or eye disease.
Monday, June, 17 2013 by Lainie Petersen
We here at Zenni have written about optical illusions extensively (see here, here, and here). However, it’s not just humans whose eyes can play tricks on itself. Computers can be tricked too, a new study finds.
Each computer model was shown a pair of lines, one longer than the other, and each line had both an arrowhead and an arrow tail or an X at both ends. The computer model then had to guess which line was longer. Over time, the researchers were able to train the system, named HMAX, to correctly identify the longer line 90 percent of the time.
Testing like this can result in something that sounds a bit like what a mad scientist would do; as researcher Astrid Zeman told LiveScience, “If we think of this visual system as something we implant in a robot, this means that we can grow whole bunch of robots up in different environments. Then, once our robots have matured and have learnt to see things, we can then smash their brains open to see what they are thinking. This is something that we can’t quite do with humans.”
The second part of the study showed a pair of lines to the computer system, but this time the top line always had two arrow tails and the bottom always had two arrowheads. For humans, if both lines are the same length, we are duped to believe the top line looks longer. And the study showed that the computer system was also duped around 1.6 percent of the time.
With a finding like this, the researchers are able to eliminate previously believed explanation for this illusion in humans—was it our brains misinterpreting the arrowheads and arrow tails as depth cues? Or do we focus more on overall information about shapes than their elemental parts? These findings show, as LiveScience wrote, that it may result simply by how our visual system processes information that requires further elucidation.
“If we build robots with artificial brains that are modeled off our brains, the implication is that these robots would also see illusions much like we do,” Zeman added. “By imitating the amazing accuracy, flexibility, and robustness that we have in recognizing objects, we could also be copying potential errors in computation that manifest in visual illusions. … These illusions bring to light new questions about how we perceive the world and the assumptions we make about the world.”
Monday, April, 8 2013 by Justin Alvarez
If you’ve ever applied for a driver’s license, you probably recall the eye examination. The process typically involves disclosing any vision issues and then reading letters off an eye chart, though each state has its own eye testing regulations. Planning on getting or renewing your license anytime soon? Read on for some info and tips on taking a DMV eye exam:
Driver’s Eye Exams
All states require individuals to take an eye exam as a condition for receiving a first driver’s license, though some states don’t require a vision test when a driver renews his license. States generally provide eye testing at driver’s license facilities, though some states will accept a doctor’s certificate showing that you’ve recently passed an eye exam. State driver’s license agency websites usually contain information on the eye testing process, as well as tips for passing the test. Be sure to bring your eyeglasses to the testing site, as you may not be able to even attempt the test without them.
Some states require elderly drivers to undergo more frequent vision examinations: If you live in such a state, it’s important to pay attention to the testing schedule so that you don’t inadvertently allow your driver’s license to lapse.
States often issue restricted licenses to individuals who have visibility problems. The terms of these restricted licenses vary, but may require the driver to wear corrective eyewear while driving, or may limit driving to daylight hours. Individuals who do have visibility issues, may also have to undergo additional eye testing by an optometrist or medical doctor and may also have to complete a special driver’s education course.
Assistance for Drivers With Visual Impairments
In addition to providing driver’s education programs for individuals with poor eyesight, individuals who can’t qualify for a driver’s license because of low vision may qualify for certain public transit benefits, including reduced fares and even para-transit services, which provide on-call transportation in areas that are otherwise under-served by public transportation systems. If your eyesight prevents you from driving, ask your local public transit company for details on its services for the disabled.
Preparing for a Driver’s Vision Test
Just as consumer advocates encourage job seekers to check their credit before applying for work, it may be a good idea to have your eyes checked before making the trip down to the DMV. Not only will you avoid the annoyance of failing an eye test, and then having to go see an eye doctor anyway, but you’ll also be able to talk to your doctor about your vision concerns, as well as receiving on-the-spot counseling and information about any problems revealed by the exam.
Don’t let passing a DMV vision test give you a false sense of security: As the Kentucky Transportation Cabinet notes, reading the Snellen eye chart is just one aspect of a thorough, clinical eye exam. It is possible to pass the eye exam and still have an undetected eye disease that could cause or contribute to future vision loss. Unless your doctor has told you otherwise, it is generally a good idea to have your eyes checked every two years.
Tuesday, April, 2 2013 by Lainie Petersen
As a child, I was obsessed with Laura Ingalls Wilder’s Little House on the Prairie book series, as well as the television show it inspired. Like many Little House fans, I was profoundly dismayed when Mary, Laura’s older sister, became blind, although Mary’s visual impairment became an important part of the storyline in both the books and television series.
In both the books and television show, Mary’s blindness is blamed on a bout of “scarlet fever,” that “settled in her eyes.” (In some other writings, Wilder indicates that Mary had a stroke as well.)
While Mary recovers from her illness, her eyesight continues to decline, until eventually she is completely blind.
While generations of Little House fans have unquestioningly accepted this explanation of Mary’s blindness, a professor of pediatric medicine recently decided to investigate Wilder’s version of events. What she discovered suggests that scarlet fever was not the culprit and that an entirely different disorder caused the loss of Mary’s eyesight.
What Really Caused the Blindness
Dr. Beth Tarini, an assistant professor in the Department of Pediatrics and Communicable Diseases at the University of Michigan in Ann Arbor, Michigan, got curious about this question while she was still in medical school. Eventually, she began investigating and discovered that Mary’s symptoms didn’t really square up with scarlet fever.
Instead, Tarini believes that viral meningoencephalitis, a serious neurological condition, caused Mary’s blindness. Tarini and her research assistant came to this conclusion after reviewing both Wilder’s writings, as well as Mary Ingalls’ records at the school she attended. Both Wilder and school records mention that Mary had “brain fever,” an anachronistic term used to describe meningoencephalitis, meningitis or encephalitis, conditions that involve the inflammation of brain or spinal membranes.
Tarini believes that the viral meningoencephalitis diagnosis offers a better explanation for Mary’s symptoms: The condition could have caused the facial paralysis that the Ingalls family attributed to a stroke, as well as a weakening of the optic nerves that caused Mary’s eventual blindness.
Why the Switch?
Nobody knows for sure why Laura Ingalls Wilder chose to call her sister’s condition “scarlet fever,” but Dr. Tarini suggests that scarlet fever, caused by the same bacteria as strep throat, was a better known and understood condition. The mis-identification may have simply been a bit of literary license that made it easier for children to understand the story line, particularly since scarlet fever played an important role in the popular children’s book Little Women by Louisa May Alcott.
(Scarlet fever could indeed be deadly, particularly if it developed into rheumatic fever, though it is now easily treated with antibiotics.)
While Wilder’s decision to simplify her sister’s medical condition for the sake of her audience seems innocent enough, Dr. Tarini notes that the cultural influence of the Little House books and television show causes parents and children alike to panic when receiving a diagnosis of scarlet fever, as they assume that scarlet fever can lead to blindness. This creates unnecessary stress for patients and their families.
Dr. Tarini has some wise counsel for her fellow medical practitioners: ” ‘This research reminds us that our patients may harbor misconceptions about a diagnosis and that we, as physicians, need to be aware of the power of the words we use – because in the end, illness is seen through the eyes of the patient.’”
Wednesday, March, 13 2013 by Lainie Petersen
Have a difficult time seeing properly at night? A team at the Ben-Gurion University of the Negev in Beersheba, Israel, is developing a technology that could turn any pair of glasses into night vision spectacles.
BGU’s professor Gabby Sarusi is leading the development team to create this ultra-thin “smart-layer,” which is reported by The Jerusalem Post to be only “one-micron thick.” This development has caught the eye of many institutions, including the Israel National Nanotechnology Institute, as current night vision technology tends to be bulky and expensive. According to Sarusi, the glasses will weigh less than 50 grams and will only require a 20-volt battery to function through the night. Additionally, unlike night vision goggles, which only amplify visible light, the multiple layers of nanocolloid materials will absorb both existing and invisible rays of light, allowing the nanophotonics film to capture these rays and convert them into visible light.
“In addition to the vastly improved optics and ergonomics of an extremely thin lens,” Sarusi added, “the technology will be far less expensive, costing hundreds versus thousands of dollars per pair of night vision goggles.” While the development could be applied to numerous fields, its most applicable sector is security. Sarusi previously worked for Elop (which merged in 2010 with Elbit Systems to become the largest electro-optics company outside of the US), developing night imaging and thermal imaging sensors.
While still in development, the team was recently awarded a $6.5 million grant from the Israel National Nanotechnology Initiative. Sarusi stated the team’s success is due to the technology’s ability to work with whatever light is available to it. “The device we will develop is a photons-starving device where every photon counts and the conversion efficiency from infrared photon to visible photon is the crucial issue. Unlike other groups in the world that are working in this field, we will implement the most advanced research in the field.”
Monday, March, 4 2013 by Justin Alvarez