eyeDOCS optometric clinics is proud to be the only provincially certified Night Vision Testing site in the Ottawa area. Candidates for the OPP, Ottawa Police and certain other law enforcement agencies are sometimes required to successfully complete a Night Vision Assessment during their application process.
The assessment takes approximately 20 minutes to complete and involves identifying letters on specially developed test charts under controlled lighting conditions.
What is Night Vision Testing?
It is easy to take for granted how vision correction has progressed over the past few decades. Once upon a time, focusing problems such as: near sightedness, far sightedness, astigmatism, and presbyopia could only be corrected by using glasses. Eventually, new innovations and discoveries gave new options. The development of contact lenses allowed all of us a chance to see the world clearly without changing our appearance or hindering our sports and activities.
Despite their versatility though, contact lenses (and glasses for that matter) have never been considered to be a viable way for people in certain fields of work to correct their vision. Glasses can be broken or knocked off during physical scuffles. Contact lenses could conceivably fall out at inopportune times or become contaminated in certain environments. Young people who aspired to be firefighters, or police officers were told in no uncertain terms that if their natural vision was not nearly perfect, they would have to seek other career options.
Laser Vision Correction (LVC) changed all of this. In the late 1980s, lasers started to be used on a large scale to correct vision problems with more predictability and stability. Practically overnight, people with focusing challenges now had a way to correct their sight without relying on glasses and contact lenses.
Although lasers did a great job of letting us see the traditional eye charts in the doctor’s office, research in the 1990’s started to show that night vision after refractive surgeries could be compromised. Patients began to report seeing bright cloud-like haloes and rings or spokes around car headlights. Pedestrians, cyclists, and objects that are dimly coloured were difficult to identify from a dark background.
The equipment and techniques used in the earlier days of laser surgery could sometimes leave clouding in the cornea, which is the front window of the eye. Also, the surgically treated cornea would have areas of varying thickness. These newly introduced imperfections in the eyes produce vision changes that are more noticeable in dark conditions. The discoveries of these problems led many in law enforcement agencies to investigate testing protocols for new recruits who had laser surgery.
Laser surgery, like other forms of vision correction, has continued to advance. Newer techniques, newer lasers, and more powerful computers have allowed today’s surgeons to greatly reduce corneal haze and minimize the impact of reduced cornea thickness. Despite this, there are still a small number of individuals who suffer from poor night vision after a refractive surgery.
To address this, researchers at the University of Waterloo School of Optometry and Vision Science have designed a test to assess night vision. Very simply, the test subject is scored on their ability to identify letters under different lighting conditions. These lighting conditions are predetermined and controlled by the examiner. The letters themselves have varying amounts of contrast. Some of the testing involves viewing the high contrast letters, like those seen on a traditional eye chart and some of the testing involves viewing low contrast letters that are more like many objects we view in the real world.
The night vision test is used by the Constable Selection System as part of their vision screening for potential police officers in Ontario. It is also used by the RCMP and numerous municipal law enforcement agencies across Canada. Applicants will be told to seek a night vision test if they have had a certain type of laser surgery or if they fail a preliminary screening during part of their physical testing.
No advance preparation is needed for a night vision test, although you should bring in the paperwork that needs to be filled out by your optometrist. If possible, it is advisable to wait for at least a few months after a surgery to allow the eyes to heal and the vision to stabilize before undergoing the test. The testing takes approximately 20 minutes to complete. If you still wear glasses even after a laser surgery, then you should bring them to the appointment as well.
eyeDOCS Ottawa is proud to be the only certified Night Vision Testing Centre in the Ottawa area. Please feel free to contact us with any other questions regarding Laser Vision Correction or Night Vision Testing.