Most optometrists can tell you a story of a young child, perhaps 5 or 6 years old who goes to the eye doctor because she is not picking things up in school and a visual problem is suspected. It turns out that the child is severely myopic and has likely never even seen the faces of her parents beyond identifying them as a particularly shaped blurr. It is a heart warming moment when the child sees her mother clearly for the first time! Here is a video of Dr. Randahwa telling this story about what happened with a five-year old girl in our Vancouver opometry clinic:
The same is the case with patients who have strabismus or ablyopia. While the former may present itself in the form of a noticeable eye turn, amblyopia (or lazy eye, as it is is sometimes known - a condition where one eye is not working properly and may even be legally blind) is not obvious. Patients with these conditions suffer from binocular vision problems (when the two eyes do not work together properly) and will often have stereo vision problems that make it impossible for them to see in 3D. The problem is that such a child will not be able to tell you that there is anything wrong with her vision, because it has been that way for her entire life. Read my older post about the book "Fixing my Gaze" to learn about a famous case of 3D deficiency and how an optometrist used vision therapy treated the problem.
Lack or depth perception and 3D vision could be a sign of a potentially life threatening disease. It could be caused by eye cancer shutting off communication between one eye and the brain. Cancer such as this should be caught early before it causes noticeable vision changes - that is the key to successful treatment and the reason why annual eye exams for children are so critical.
You can also ask your child to describe what the 3D movie or game is like. Be careful not to ask vague questions like, "is this movie different from an ordinary movie?" The child will be wearing 3D glasses, which can alter color and so the movie will be different for those reasons alone.
While 3D media offer parents an opportunity to catch a visual problem, parents can always, and should regularly visit their optometrist where visual disorders like strabismus and lazy eye are routinely tested and diagnosed.
Properly functioning binocular vision is not just necessary for enjoying the latest entertainment but it is vital for learning, sports, driving and it is necessary for many careers (you can't be an eye surgeon without good binocular vision, for example).
For more information of children's vision, eye care, and children's optometry, please visit www.kidsvision.ca.