There it is again, that little speck that glides across my vision from time to time, then disappears. There are times when I’m looking at the sky or a blank wall and notice little shapes floating in front of me. They’re not quite clear — almost like little bits of dust stuck on a camera lens. I try to blink them away, but they’re still there. When I look somewhere else, these shapes move with me. Mostly, it’s an annoyance and distraction, but sometimes it’s briefly entertaining to try to follow their path. But what are they, and where did they come from?
Major League Baseball is back, and so is the 100-mph fastball. How is a batter able to hit a ball traveling faster than the eye’s ability to track it? The answer lies with the retina’s ability to signal the brain to anticipate the future, or predictive motion encoding.
Machines such as cars and robots don’t have eyes, but we expect them to “see.” How can that happen? Researchers are applying what has been learned from decades of perfecting eye-imaging technologies to tomorrow’s autonomous systems sensor technologies, such as those found in self-driving cars. Let’s start with cars. Today’s self-driving cars use a combination of three sensor and image technologies: radar, Light Imaging Detection and Ranging (LIDAR) , and cameras.
We’ve all experienced the feeling of someone looking at us, even if we don’t see them. A look over the shoulder or a turn of the head, and sure enough, there they are. Hopefully, the look is with admiration for our stunning eyewear or new outfit. But how did we know we were being watched? Scientists are finding evidence that it’s another feature of the eye-brain connection, rather than just a feeling.
You don’t look like you feel well. How often has this statement been a precursor to some medical intervention? What exactly are people seeing that triggers this question? How physicians, especially, discern differential skin pigmentation in patients casts an intriguing glimpse into the physical development of color perception in the human eye as well as possible avenues for advanced medical training.
From Review of Myopia Management Environmental factors influencing myopia onset include, but are not limited to, level of education, near work, and time spent outdoors. Increased time outdoors has been emphasized as an important modifiable environmental factor for myopia control. Irrespective of physical activity, increased time outdoors is associated with a reduced odds ratio of myopia, even when children perform a high amount of near work. The protective effect of time spent outdoors could be due to the unique characteristics (intensity, spectral distribution, temporal pattern, etc.) of sunlight that are lacking in artificial lighting.
According to The American Board of Optometry, Americans are on their computers and other electronic devices more than ever before—an average of 7 hours a day—and it's causing an unprecedented amount of eye-related symptoms. Clinicians commonly refer this to as Digital Vision Syndrome (DVS), or Computer Vision Syndrome (CVS), with headaches, dry eyes, neck pain, and eyestrain or asthenopia being some common complaints. An estimated 50-90% of adults who work on computers and children who stare at tablets or other devices report symptoms of DVS.
Let’s start by talking about the electromagnetic spectrum. The spectrum consists of all the types of electromagnetic radiation, arranged according to frequency and wavelength. There’s very high energy with short wavelengths which include gamma rays, used by PET scanners with a wavelength below 10 picometres, (one-trillionth of a meter) x-rays, and ultraviolet rays followed by visible light which the human eye detects. The waves move from higher energy with shorter wavelengths to longer ones with lower energy. The lower energy and longer wavelengths include radio waves, microwaves, and infrared (night vision goggles).
Visual artist Trebs Thompson recently finished the third of a three panel, stained glass room divider, but she was working against time. About six years ago, Thompson was diagnosed with Type 2 parafoveal macular telangiectasia (MacTel), a rare, progressive disease in which blood vessels around the fovea become abnormal, and new blood vessels may form under the retina and leak. Tissue in the macula or the fovea may thin out or form a scar, causing loss of detail and central vision. Loss of central vision progresses over a period of 10 – 20 years, and Type 2 MacTel affects both eyes. To date, there are no treatments that significantly improve vision.
To quote Indiana Jones, “It’s not the years, … it’s the mileage.” As Jones succinctly notes, physical age may not necessarily match chronological age. We know that aging well is the result of myriad factors such as diet, activity, stress levels, environment, and genetics, to name a few. Regular physical exams include multiple screenings for a variety of health conditions, and a retinal exam can reveal conditions such as diabetes, hypertension, rheumatoid arthritis, vascular disease, and more. While these tests reveal what is now, the retina may be able to predict future health.
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