Older adults and the loss of depth perception

Here is a graphic we made on older adults and the loss of depth perception.  Please share it to raise awareness.

Visual processing speed slows down as we age, making driving less safe - how to measure it and how to improve it

We slow down as we age.  But can we get some of our youthful speed back, at least with respect to visual processing?  Will treating visual processing weakness make older adults safer drivers? A new article in the September 2013 issue of the journal Vision Research suggests that the answers to these questions is "yes".

With respect to eyes and vision, the need for reading glasses is a common vision change that few manage to escape as they age. Another change, that is not as well known is changes in our visual processing speed.  

Changes in visual processing speed affect all aspects of our daily life.  Slower visual processing can make us generally inefficient as we are slow to take in and react to our visual world.  It can also make us prone to accidents.  

What can we do about declining visual processing speed? There is research that suggests that with the appropriate training, therapy and practice, visual processing speed can be improved for for many activities of daily living such as driving.  

One way to test visual processing speed is a protocol developed by doctors of optometry called Useful Field of View (UFOV).  It consists of a computer-generated series of three tests. The results are categorized into areas of visual processing weakness:

• rapid visual processing, 
• selective visual processing, and 
• divided attention. 

If weaknesses are found, they can then be addressed with specific vision therapy or training based on the protocol for the UFOV.  The results can then be measured and they usually affect the speed with which older adults can perform everyday visual tasks, with the result of, hopefully, decreasing the risk of accidents.

The results of UFOV illustrate the difference between legal driving and safe driving.  Legal driving requirements are based on visual acuity - how clearly you see at various distances and whether you have the necessary peripheral vision.  Legal driving tests do not assess how useful your vision is to the task of driving. Safe driving is impacted by the driver's speed of visual information processing. The law has not caught up to vision science yet, but it is only a matter of time.

For people that have weak visual processing speed and who want to improve, developmental optometrists at our Vancouver eye clinic such as Dr. M.K. Randhawa, offer therapy programs to improve visual processing speed.  Car accidents can radically change your life for the worse, anything that can be done to avoid them is welcome.

Related articles:

Optometrists identify seniors with high car-crash risk due to in-car distractions. Are Ford Sync and Dodge Uconnect dangerous?
Thursday, May 3, 2012

CITATION:

Vision Research
Visual Processing SpeedVision Res. 2013 Sep 20;90()52-56, C Owsley

map | directions | FREE parking | book an appointment 

Optometrists identify seniors with high car-crash risk due to in-car distractions. Are Ford Sync and Dodge Uconnect dangerous?

Drivers with Limited 'Useful Field of View' Should Avoid In-Car Distractions

A study in the April issue of Optometry and Vision Science, official journal of the American Academy of Optometry, has found that a computerized vision test can identify older drivers who are likely to have driving problems related to distractions in the car and who therefore have a high crash risk.

The study authors, led by Joanne M. Wood, PhD, FAAO, of Queensland University of Technology, Brisbane, Australia, found that older drivers who show limitations on an optometric vision test called the "Useful Field of View" (UFOV) test make more driving errors when they are distracted. The finding provides a basis for making older drivers safer by predicting who will be more distractible on the road. Older drivers identified as distractible can benefit from minimizing distraction while driving - this makes driving safer for them and the drivers with whom they share the road.

Test Predicts Driving Problems Related to Distraction

The study looked at 92 drivers with an average age of 74 years who underwent the computerized UFOV test. Useful field of view is defined as "the area over which a person can extract information in a single glance without moving his or her head or eye." Drivers with limitations in UFOV are more likely to have problems in demanding driving situations, with an increased risk of crashes.

After the UFOV test, the drivers performed a closed-course driving test three times. On two of the three runs of the driving test, their car was fitted with visual or auditory distracters. The distracters were simple math problems presented on a video screen or audio speaker. The distractors mimic the degree of attention demanded by common in-car experiences such as conversations, navigating an ipod or smart phone, navigation system or in-car entertainment system.

Drivers who had limitations in UFOV were most likely to have problems on the driving test when there were visual or auditory distracters present in the car. These drivers also took longer to complete the driving test. This may be a reason for the slower driving commonly seen in older drivers.

The part of the UFOV test that assessed a driver’s "selective attention” was the best predictor of driving performance.  Drivers with low selective attention scores had a very high crash risk. In contrast, older drivers who did better on the selective attention subtest had better overall performance on the driving test, even with distracters.

Older Drivers at Risk Should Minimize Distractions

Previous research has shown that the UFOV test is highly effective in predicting crash risk among older adults, with or without vision problems. The new study suggests that distractibility is an important contributor to problems in driving performance and crash risk. That conclusion is consistent with recent research on the effects of increased distraction while driving, especially distractions from things like cell phone use.

Every year, cars come outfitted with more gadgets inside from GPS navigation, to touchscreens. My new Dodge Journey includes a car-driver interface (pictured above) that allows the driver to make phone calls by scrolling through an on-screen phone book downloaded from a cell phone and to browse an ipod music library on an dashboard integrated touch screen. These are all distractors and they are an example of how the driving environment is becoming more complex and distracting.

The interface can also be controlled by voice but that is also distracting because it involves paying close attention to audio instructions and prompts.  This study’s results have important implications for the design of these kinds of in-vehicle devices and the safety of older drivers using them.

Here is a funny TV commercial promoting the Dodge Journey's uconnect driver interface system.  Will something like this be a dangerous distraction for older drivers?

Sharp Vision Sharp Mind

Poor vision and inadequate eye health care is linked to cognitive decline in elderly people.

In a recent study of 625 elderly patients conducted by the University of Michigan, those with poor vision who did not receive proper eye care were a stunning nine times more at risk of developing Alzheimer's disease and five times more at risk for some form of cognitive impairment. 

In contrast, those with good vision had a 63% reduced risk of developing dementia.

Another study that reached similar results was published in the journal Optometry & Vision Science in December 2010.  In the latter study, the researchers simulated visual impairment in a group of elderly people.  They found that visual impairment can lead to a slowing of cognitive performance in older adults.  Cognitive impairment was greater in older adults that it was in their younger counterparts. 

The findings of these studies have important implications for older people who have a high prevalence of cataracts or may be prone to ignoring their health. They may be well advised to have surgery to remove their cataracts in order to prevent any possible cognitive decline and to always keep current with their spectacles prescription.

Sharp vision and a sharp mind seem to go hand-in-hand.  Protect both by scheduling a comprehensive eye health examination.  Remember, age is a risk factor for a host of diseases that can lead to vision loss. Glaucoma and age-related macular degeneration are two of the most prevalent.  An eye exam is the only way to catch these diseases early enough to do something about them.