Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Snapple asked in HealthOptical · 8 years ago

Why can other people see better in the dark than me?

It seems as though when I'm with people at night, I often have difficulty reading things that are far away that others can read. During the day, I don't have this issue.

So, to avoid the answer "maybe you need glasses," imagine I'm in a line with 5 people that have completely identical vision except for their respective abilities to see at night. In the dark, those other four may be able to read a sign down the road, while I cannot. If an identical experiment were carried out during the day, we would all be able to read the sign down the road equally well (because we have identical vision).

Why is this?

5 Answers

Relevance
  • ?
    Lv 7
    8 years ago
    Favorite Answer

    Basically because some people have more "rods" in their eyes than others - these "rods" help us to see at night. People that have more of these rods will have better night vision.

    The retina — the membrane that lines the back of your eye — is somewhat analogous to the film in a traditional camera or perhaps to the sensor in a digital one. Light hitting the photoreceptor cells of the retina triggers biochemical changes in those cells, which send signals to the optic nerve. When those signals reach the brain, they are processed as images, and we experience the sensation of sight.

    These photoreceptors come in two varieties, cones and rods. Cones respond to light in the wavelengths associated with color, giving us color vision. They're also responsible for visual detail: It's your cones that let you read the words on this page. Rods are useless for color — they only provide black-and-white images — but they're exquisitely sensitive and are therefore crucial to good night vision.

    The fovea, a tiny portion of the retina, contains only cones. In the macula, which surrounds the fovea, rods outnumber cones 9:1 in healthy young adults. Researchers at the University of Alabama in Birmingham conducted a study that involved counting the cones and rods in the retinas of recently deceased older adults. They found an abundance of cones in the macula and a diminished number of rods. This study and others indicate that we hang on to our cones, but may lose almost a third of the rods in the area right around the fovea in the macula. This is why older people tend to hate driving at night.

  • Anonymous
    8 years ago

    It takes time for your eyes to get adjusted to the darkness and see things properly.or maybe you have some eye problems

  • 8 years ago

    you weren't born with night vision? you should go to a doctor right away

  • 8 years ago

    Maybe you have night blindness.

  • Anonymous
    8 years ago

    Maybe you need glasses.

Still have questions? Get your answers by asking now.