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Horse Vision - would bi-focals help?

A horse has one of the largest eyes in the animal kingdom—bigger even than an elephant. Its eyes have a huge range of vision (about 340 degrees out of 360), with only two small blind spots—the six feet directly in front of its nose and immediately to its rear as wide as its hips. For this reason, the safest way to come up to a horse is at a slight angle, looking for a cocked ear or an eye in your direction to indicate he knows you’re there. Otherwise, you may startle the horse and end up getting kicked.

    Because the eyes of a horse are set on either side of its head, it does not
    normally see objects like we humans, with our binocular vision, do. Most of the
    time a horse sees a different picture with each eye. And since a horse’s eye
    muscles don’t easily bring objects into focus, it uses the lower part of the eye to
    see into the distance, and the upper part of the eye to see things that are close
    up.

    When looking afar, a horse holds its head high. An interesting note is that the
    muscles that assist in this process also raise the ears and prick them forward at
    the same time. This is a nice feature if you are on the lookout for predators.

When a horse wants to look at objects close up, the opposite occurs: it lowers
its head and the ears relax.

    Horses see fewer details than humans, but are much more sensitive to movement.
    That’s one reason to be aware of what your own body is doing when you’re
    around horses. Extraneous movements, especially if they keep changing, can
    create a lot of confusion in a horse’s brain and lead to flight behavior (running off,
    rearing, kicking). It’s helpful to remind children who are unfamiliar with horses to
    move slowly when they are near.

    In strong light, horses’ eyes react in a much different way than humans. For us,
    the pupil gets smaller, until it becomes a small black dot. In horses, the pupil
    narrows to a slit. But unlike a cat, which has a vertical slit, the horse pupil
    shrinks to a horizontal slit.

    This special adaptation meets a horse’s need to keep wide open horizons in view
    at all times to watch for predators. The pupils may look small in the glare, but a
    huge range of vision remains unimpaired. In bright sunlight, a horse appears to
    be nearly blind, but it is actually noticing everything you do.

    Myth buster: Horses are not color blind, as many folks believe. They have two-
    color, or diachromatic vision. This means they see two of the basic three
    wavelengths of visible light, compared to the three-color vision of most humans.
    In other words, horses naturally see the blue and green colors of the spectrum
    and the color variations based upon them, but cannot distinguish red.