Peripheral vision. Everyone has it, but most pay no attention to it. When you put your arms out to your side and wiggle your fingertips, you should be able to see them move while you are looking straight ahead.

If you have dementia, you pay much more attention to peripheral vision, because slowly and steadily you lose it. You see, for whatever reason, one’s peripheral vision becomes impaired as this disease progresses. This is why you will hear people say, "Always approach a dementia patient from the front or side, not the rear.”

You have probably heard this advice, but did you ever wonder why it works? Well, it's on account of the patient’s visual field. They can no longer sense you approaching them from the rear, and eventually they will not be able to see you approaching them from the side either.

Why does this happen? Well, vision of any kind is controlled by your brain, of course. When you have a disease of the brain, this is affected, just like all other senses.

But a shrinking visual field presents many more issues than just approaching a patient from the rear. Take eating, for example (or the lack thereof).

You will read over and over on Support Groups and Memory People about loved ones with dementia who are not eating. Caregivers are desperately trying to feed them, but they refuse to eat. Most people think this has to do with them just being stubborn.

It doesn't. Many times this has to do with the loss of their peripheral vision. In the later stages of this disease, one’s peripheral vision weakens so significantly that it gets to where their sight is binocular or telescopic.

With that in mind, put your hands up to your eyes, form them as if you were looking through binoculars and consider what you see: Nothing but what is directly in front of you. Now again, with that in mind, think about when you or a staff member at a facility is feeding your loved one.

What do they see? They don't likely see that you are indeed feeding them. They most likely won't understand, even if you tell them you are feeding them.

All they can see is this fork coming at them at the very last second. They can't see the food on the plate, they can't see that you are feeding them. What they do see is something, possibly a fork, or whatever they think it is, heading right for their face.

This would be enough to startle anyone. Yet, you never hear about this being a problem. Why is that? Because I feel the caregiver or staff does not know about dementia patients’ visual changes and the implications this has.

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I am not saying this is the sole reason why your loved is not eating, but this could very well be the reason that feeding them is so difficult at times.

They are simply scared. They cannot see what is coming at them until the very last second. If you suddenly saw something coming towards your face, opening your mouth is probably the last thing you would do.

Not only does the brain have difficulty registering movement and objects surrounding the person, but it also experiences increasing challenges when it comes to processing the information it receives and turning it into a meaningful message or perception. Sometimes the conclusions the brain arrives at are incorrect and result in illusions, misperceptions or misidentifications of faces.

Depth perception can be seriously affected by visuoperceptual mistakes. When a patient is walking, they may not be able to tell when, for example, the floor changes from carpet to tile. If the tile or carpet is patterned, this can disorient them even further, which can certainly attribute to falls. A shadow or dark throw rug on the floor can also appear to them as a hole in the ground, which can be very frightening.

Visual distortion and weakness can truly mess with your mind. When your mind is already being messed with, it poses some serious challenges for patients and their caregivers. If you put yourself in their shoes, you can begin to understand the struggles the patient has with simply seeing what is going on around them.

I bring this up as if you don't have enough on your plate already. But try to remember, when your loved one isn't eating or they are startled from you just approaching them, it could be because they cannot see you. That would scare anyone.