3-D movies hampered by vision problems

Three to 9 million people in the USA have vision problems that keep them from enjoying such 3-D movies as Avatar and Toy Story 3, estimates the American Optometric Association and as many as 56% of people between 18 and 38 years of age suffer from symptoms related to depth-perception problems.

These problems have to do with binocular vision, the ability to align both eyes on a target and combine the visual images from the two eyes into a single, three-dimensional perception.

"We have 3-D because we have two eyes in our head in slightly different places," Maino explained. "When the brain puts two images together, that's when we get the 3-D effect."

"3-D is really our ability to judge distances," he said. "It's a real nice survival trait, so we could tell how far away that saber-toothed tiger is and have him for lunch rather than the other way around."

Movies done in 3-D recreate this effect by feeding different images into each eye, Maino said. In the early days, 3-D glasses would have one red lens and one blue lens, and there would be one red image and one blue image on the screen separated by a little distance. One eye would be able to see only the red and the other only the blue, and the brain would fit them together to form an in-depth perception.

The technology today is more advanced. Now, 3-D is created using polarized lenses that pick up separate images or by timing the images between the two eyes. "One image will be placed on one eye and then very quickly the other image is placed in the other eye," Maino said. "When the brain puts that together, it gives the sense of 3-D."

However, people who are having problems with their binocular vision will either not be able to perceive the illusion of 3-D, or they will find that the movies or TV shows actually give them "visual hangover," said Leonard Press, a spokesman for the American Optometric Association and optometric director of the Vision and Learning Center in Fair Lawn, N.J.

An association poll found that headaches, blurred vision and dizziness are the most common side effects from 3-D movies for people who have binocular vision difficulties. "After the movie, they're a bit dizzy, and it takes them awhile to get back to normal," Press said.

Several different vision disorders could be the cause of the problem, including:

• Amblyopia, or lazy eye, which occurs when one eye does not see as well as the other. "Because of that difference between the two eyes, the ability to see 3-D is greatly reduced or absent," Maino said.

• Strabismus, or crossed eyes, in which the eyes do not line up in the same direction when focusing. Ultimately, a person with strabismus begins to suffer from double vision or loses the ability to see in 3-D.

• Convergence insufficiency, in which the eyes are incapable of turning toward each other to fix on the same distance.

Any of these can be treated by an optometrist or ophthalmologist. In fact, Maino said, the new 3-D movies are giving some people their first clue of a vision problem they may have had for a long time without recognizing it.

The problems, though, can be treated using optometric vision therapy, in which eye patches or special pairs of glasses are utilized to teach the eyes how to work together, Press and Maino said. Some of the techniques already are used to help kids with amblyopia or strabismus.

"It's a form of physical therapy for the eyes," Press said. "The key is helping your eyes work together with your brain. You do different activities that help both eyes work together. It's almost like lifting weights."

By the end of vision therapy, "we should have someone who has single, clear, two-eyed vision," Maino said.

Dyslexia Untied: The Importance of Good Eyesight

Unfortunately, 20% (1 in 5) of all school age children have undetected vision problems. Don't panic! Not all of these are acute or permanent and not all are detrimental to the child's development but there are a number of issues that need to be addressed, as soon as possible (ASAP).

If your child has an undetected, undiagnosed or undefined vision problem, they can appear to demonstrate symptoms or behaviours that can be mistaken for dyslexia, but only superficially. Consultation with a qualified expert in the field will dispel or confirm this concern. Rapid intervention is important.

The worst case, and possibly your worst fear, is that your child does have dyslexia and their vision problems are making it more difficult.

Regular Eye Checkups
It is important for all young children that their eyesight is checked regularly and corrected accordingly. It is more important than for adults and older children, because the younger child may be growing and developing at a much quicker rate.

Unfortunately, even if you get your child's eyesight checked as part of a normal screening process, there is a possibility that the average optician will miss the telltale signs of dyslexia, unless it is brought to their attention. It falls back on the parent to be more aware and to be more insistant or assertive, on behalf of their child(ren).

Symptoms to look for
Symptoms that are often associated with Dyslexia can be as obscure as the slight tilt of the head when trying to read or follow words in a text or book. More complex issues are;

• Amblyopia (lazy eye) - When one of your child's eyes doesn't work as well as the other. 3% 0f children under the age of 6 are reported to have Amblyopia. Treatment: eye exercises, eye patch, etc. Long Term: If it's not treated early it can lead to poor vision into adulthood.


• Strabismus (deviating eyes) - When your child's eyes appear dis-coordinated and don't look towards the same object, together. It may be a fixed or permanent defect or it may only be temporary and brought on by stress and tiredness. Either way you should seek qualified expert advice.

These conditions are not rare and neither is the situation whereby your child has the 'normal' 20/20 vision but is having difficulties in sustaining their gaze, co-ordinating their eyes, holding and varying their focus, when objects move closer and away from them.

Scotopic Sensitivity Syndrome - Some children with Dyslexia have difficulty tracking words and letters along a line or sentence. This is known as Scotopic Sensitivity Syndrome, a known issue that can be addresed separately. The Irlen Method of treatment concentrates on this specific issue.

If you have concerns, take this up with your doctor or with a qualified optometrist or opthamologist. The qualifications of the local high street franchise opticians can vary quite dramatically. Check their credentials.

Early detection and diagnosis is important in all childhood issues and none moreso than in vision and hearing, as these can very much affect the child(dren)'s development, education and behaviour.

Summary

Don't Panic! The majority of Dyslexia consultants and experts will agree that vision problems 'alone' do not cause or lead to the onset of Dyslexia but it does complicate the situation for the child(ren), the family and the teachers.

Therefore, the message here is; be aware of the impact that vision has on the development of the child and their well being and importantly, early detection, diagnosis and correction or treatment by qualified experts, is essential.