A succinct piece about mTBI and vision on the Wills Eye site from Debra Lehr, O.D. – a neuro-optometrist with Wills Eye Hospital at the Jefferson Comprehensive Concussion Center in Philadelphia. A graduate of Lehigh University with a degree in Behavioral and Neural Biology, Dr. Lehr is a graduate of Salus University and a member of NORA as well as COVD.
How often is vision affected in concussion?
A recent study found that over 90% of outpatients with mTBI had one or more visual impairment, including difficulty with eye movements, focusing, and eye alignment. Basically, the eyes were not working well together during visual tasks, such as tracking a moving target, shifting eyes from target to target, or holding steady gaze on a target.
What are the most common visual symptoms?
The visual symptoms can be subtle and at times, fatigue or brain fog may be blamed. However, one of the most common visual issues in concussion is difficulty keeping the eyes pointed to the same position in space while focusing the eyes to that same point. That is why objects may appear to move, be seen as double, or blur in and out of focus. Sometimes the impairment is noticed when attempting to focus quickly from near to far or far to near. You may feel uncomfortable when making eye contact or you may not be able to tolerate complex visual environments, such as the grocery stores or patterned flooring.
Other visual problems include light sensitivity, headaches, double vision, fatigue, dizziness, difficulty reading, or loss of peripheral awareness. You may feel the need to wear sunglasses when inside, particularly if you are exposed to fluorescent lights. Visual tasks involving the computer or prolonged reading may require more time than usual, and tend to be more confusing and fatiguing. Another common complaint is eye pain and discomfort, which at times is caused by staring to maintain focus, which dries the surface of the eyes.
What tests are needed to detect these visual problems?
A comprehensive vision evaluation must evaluate the health of the eye, as well as the visual processing system. The examination must include oculomotor (eye movement), binocular vision (eye teaming and alignment), and accommodative (focusing) testing. In addition, it is important to evaluate how the brain is processing the visual information through visual perceptual testing.
What can be done to alleviate these issues?
Once the vision evaluation detects the visual problems, a course of treatment can be prescribed. Remediation of the visual system may require specific lenses or prisms in glasses, lubricating drops, training exercises, and/or tinted filters to reduce light sensitivity.
The VisionHelp Blog 
Great summary. The problem with patterned flooring or wallcoverings almost certainly has to do with increased sensitivity to dissonance in processing of the image bihemispherically (even monocular processing is bihemispheric, realize). The problem can be perceived by many with one eye alone, or may get worse. The issue is the aliasing of the image. That is, undersampling of the pattern causes mirages or illusions. Larry Thibos of UI Bloomington School of Optometry lectured on aliasing extensively about thirty years ago, several of his .ppt lectures were online fifteen years ago. Filtering resolves it and that may be either optical (tints, miniprisms, miniplus) or neural (VT). Even a monocular miniprism can give great resolution to many. The same is true for photophobia. Monocular prism on the contralateral eye during slit lamp exams and indirect ophthalmoscopy can give significant relief of the distress. One merely needs to remember to try it. Miniprisms are a surprising, innocuous tool for helping these sufferers. Just try it, somebody once said….
The key to the care of those with TBI is thorough diagnosis. Imagine all possibilities of cause and treatment.