Poor Night Vision: What Can You Do?

night visionPoor night vision or night blindness can be a life-limiting symptom. Night blindness can be caused by either an inherited or acquired reason. Poor night vision disorders (night blindness, impaired dark adaptation, etc.) include the experience of reduced vision in dimly lit environments, including at night. They include partial or complete impairment in ability of the eyes to adapt from brightness to darkness. It is not a disease in itself, but rather a symptom of an underlying problem, usually located in the retina. It is common for patients who are myopic (nearsighted) to have some difficulties with night vision, but this is due to optical issues rather than to a retinal condition. Symptoms include difficulty driving at night, tripping over objects when walking in the dark, and slow response when light conditions change (such as entering a dark movie theater). Photoreceptor cells in the retina allow you to see in dim lighting. When they malfunction, vision in dark conditions becomes difficult.

The photoreceptors called “rod cells” are mainly responsible for night vision. Rods can detect single photons and transmit that data to rod bipolar cells. This makes dim light information more usable to the brain. Continue reading “Poor Night Vision: What Can You Do?”

Macular Degeneration Glasses May Restore Vision: Pixium Vision’s Bionic PRIMA System Sees Improvements

pixium implant glasses for better visionPeople with vision loss due to retinal disease may be able to use a bionic  system to improve sight in the near future. Pixium Vision is running a feasibility study on is PRIMA System, and they got better-than-expected results. The study is on patients with dry Age-Related Macular Degeneration. Currently, medical science cannot restore vision in those with retinal dystrophies. The PRIMA System may lead to vision restoration for patients with Macular Degeneration, Retinitis Pigmentosa and other retinal diseases. Continue reading “Macular Degeneration Glasses May Restore Vision: Pixium Vision’s Bionic PRIMA System Sees Improvements”

Computers & Your Eyes: A 3-Part Series

Eye strain is the symptom that most people associate with overuse of electronic visual display devices — from television to laptops & desktops — to smartphones — to handheld games and ebooks.

Smartphone ownership has grown explosively with 68% of Americans owning smartphones in 2015 compared to 35% in 2011. Most adults under age 50 (79%-85%) are smartphone owners, and of the middle-age to senior group (age 50-64) more than half own and use smartphones. This growth has lead to increased rates of a number of vision conditions.

Perhaps even more alarming, many health professionals regard smartphone addiction with its negative consequences as an emerging health trend.

In this 3 part series we’re examining the consequences of damage from these electronic devices:

Continue reading “Computers & Your Eyes: A 3-Part Series”

Prism Eyeglasses May Help Improve Vision of Patients with Hemianopia

Hemianopia is a blindness in one half of the visual field due to damage of the optic pathways in the brain. This damage can result from brain injuries caused by stroke, tumor or trauma.  A patient with hemianopia may be unaware of what he or she cannot see and may frequently bump into walls, trip over objects or walk into people on the side in which the visual field is missing.

Prism eyeglasses were invented by Dr. Eli Peli of the Schepens Eye Research Institute, an affiliate of Harvard Medical School, to assist patients with hemianopia.  Dr. Peli attached small high power prisms on the top and bottom of one spectacle lens, leaving the center of the lens untouched. The prisms pull in images missing from the visual field above and below the line of sight on the side of the vision loss.  The prisms alert the patient to the presence of a potential obstacle, so that the patient can then move his/her head and eyes to examine the prism-captured image directly through the clear center of the lens.

In the trial, 32 of 43 participants (74%) who were fitted with prism glasses continued wearing the glasses at week six; at 12 months, 20 (47%) were still wearing the spectacles eight hours daily and rating them as “very helpful” for obstacle avoidance.

A larger study is currently underway to evaluate a newer model of the eyeglasses. 

SOURCE: “Community-Based Trial of a Peripheral Prism Visual Field Expansion Device for Hemianopia”, Bowers, et al, Archives of Ophthalmology, 2008, vol. 126, no5, pp. 657-664.

Millions May Be Driving with Uncorrected Visual Impairments

Regular Eye Exams are Vital for Driver Safety

11 million Americans with could be driving with uncorrected vision problems. Depending on where those drivers live, their last DMV-required vision screening could have been eighteen years ago; some may never have had one at all, according to a report by the Vision Council of America (VCA). 

“Our already crowded roads are made that much more dangerous by drivers with uncorrected vision problems getting behind the wheel,” said Ed Greene, VCA chief executive officer. “Since 85 percent of the information needed for safe driving is visual, regular eye exams are an important part of driver safety.”

The VCA report “Keeping Our Eyes on the Road,” reviewed vision screening laws and found them to be inconsistent. While some states require vision screenings every time drivers renew their licenses, other drivers may go as long as 18 years before they are required to have their vision re-checked. Nine states require no vision screening at all for license renewal. In the absence of standards for vision screenings, drivers must be responsible for maintaining good vision.

“We rely on our eyes every time we step into a car; especially our peripheral vision, depth perception and focusing skills,” said Greene.  “This link between vision and driving makes it essential for motorists to take steps to maintain healthy vision, just as they take other safety precautions on the road.”

“People often don’t notice gradual changes in their vision which, over time, can impede their ability to drive safely,” said ophthalmologist Elaine G. Hathaway, M.D. “Checking your eyes is important not only to determine proper vision correction, but also to detect cataracts and sight-threatening diseases such as glaucoma and macular degeneration so they can be properly treated.”

VCA suggests the following tips to help drivers stay safe on the roads:

  • Take breaks when driving long distances to reduce eye strain and fatigue
  • Use sunglasses with at least 99 percent UV protection when appropriate
  • Investigate anti-reflective or polarized lenses to allow more light to enter the eye and to minimize glare
  • Keep headlights, taillights and windshield (both inside and outside) clean
  • Receive regular eye exams by an eye care professional to ensure that your eyes stay healthy and your prescription remains current

Regardless of what your state requires, VCA recommends that drivers receive a regular comprehensive eye exam by an eye care professional to maintain healthy vision.  With regular vision care, drivers can prevent poor sight from putting themselves and their loved ones at risk on the road.

SOURCE:  Vision Council of America, Keeping Our Eyes on the Road, November 19, 2007.