Q:

What is the path of light through the eye?

A:

According to The Merck Manual Home Health Handbook, light travels through the sclera, cornea, pupil and lens before stopping at the retina, respectively. Once at the retina, the information from the light is converted to electrical impulses for the brain to interpret.

The Merck Manual Home Health Handbook describes the sclera as the eye's tough, outer covering. It is transparent, allowing light to pass through. Next, light passes through the cornea. The cornea roughly focuses light towards the pupil. The pupil is a dark circle in the center of the eyeball. It is surrounded by the iris, which constricts and expands to change the size of the pupil. Acting similarly to a camera's aperture, it regulates the amount of light that enters the eye's interior.

After entering the pupil, that light passes through the lens. The lens is responsible for fine focusing light. It does this by slightly altering its shape to bend light rays at the correct angles. The light then lands on the retina, which is a surface at the back of the eye that is covered in photoreceptors. Photoreceptors sense different types and wavelengths of light that are converted into electrical signals. The optic nerve delivers these signals to the brain where they are decoded into images, notes The Merck Manual Home Health Handbook.

Sources:

  1. merckmanuals.com

Is this answer helpful?

Similar Questions

  • Q:

    How is an image formed in the human eye?

    A:

    An image is formed in the human eye when light passes through the pupil, is refracted by the lens and is absorbed by pigment cells in the retina, altering the pigments and triggering neurons to fire. The particular arrangement of the stimulated cells is interpreted by the brain into a separate image for each eye. The two eyes look at images from slightly different angles, allowing the perception of depth.

    Full Answer >
    Filed Under:
  • Q:

    What is a hole in the retina?

    A:

    A macular hole is a small break that occurs in the center of the eye's retina. The macula is a light-sensitive part of the retina that provides the sharp central vision that aids in seeing fine detail, reading and driving.

    Full Answer >
    Filed Under:
  • Q:

    How do nerve impulses from the retina reach the brain?

    A:

    When light reaches the rods and cones in the retina at the back of the eyeball, a series of complex chemical reactions takes place, forming the chemical rhodopsin that converts the light into electrical impulses, according to the Vision for Tomorrow Foundation. The electrical impulses travel to the optic nerve.

    Full Answer >
    Filed Under:
  • Q:

    What causes black floaters in eyes?

    A:

    The appearance of black floating objects in the eye are usually shadows cast on the retina, caused by clumping in the liquid within the eye, known as the vitreous humor. However, eye floaters could signify serious conditions.

    Full Answer >
    Filed Under:

Explore