A Look at the Human Eye

A Look at the Human Eye

Human eye

How the Human Eye Works

Seeing is possible thanks to a complicated series of events that start in the eyes and end in the brain. The entire process happens almost instantaneously and is only successful if every part of your visual system works properly.

It All Starts with the Cornea

Your cornea, a clear, rounded layer of tissue that covers your pupil and iris, helps light reach your eyes by bending the rays as they enter your pupils.

The iris and pupil work together to let light into the eye. Have you noticed that your pupils look bigger when the light is dim? Tiny muscles in the iris make the pupil bigger when it's harder to see, allowing more light to enter your eyes. The muscles shrink the size of your pupils when it's bright outside or inside.

The Lens Is Essential for a Clear Picture

Light rays pass through the lens and the vitreous humor after entering the eye. The lens is a transparent disc located inside the eye under the iris and pupil, while the vitreous is the clear gel that gives the eye its shape.

The muscles that control the shape of the lens relax, causing the lens to flatten when you look at an object in the distance. The opposite happens when you look at something nearby. The muscles contract, thickening the lens. The ability of the lens to change shape allows you to shift your focus from near to far objects and back again.

The lens focuses light rays on the retina in the back of the eye. If your eyeball is too long, the rays will focus in front of the retina, causing myopia, or nearsightedness. If you're nearsighted, close objects are easy to see, while everything in the distance looks blurry.

Hyperopia, or farsightedness, occurs when your eyeball is too short. Light rays focus beyond your retina and make your near vision blurry.

As you get older, the lenses of your eyes become less flexible. The loss of flexibility affects your ability to see near objects clearly. This condition, called presbyopia, usually begins in your early- to mid-forties, according to the American Optometric Association. Fortunately, a pair of reading glasses will make it much easier to read a book or thread a needle.

The Retina Transforms Light Rays

The retina covers the back of the eye and contains two types of photoreceptor cells. The rods, found in the outer part of the retina, are essential for side vision and help you see in dim light. Cones, the other type of photoreceptor cells, are located in the macula, the center part of the retina. Cones are needed for color vision and also help you see fine details easily.

The retina turns light rays into electrical impulses, then sends the impulses to the occipital lobe of the brain through the optic nerve. Problems with your retinas or optic nerve can affect your vision.

If you have macular degeneration, a common age-related eye condition, your central vision may be blurry or you may notice blank spots in the middle part of your vision. Increased eye pressure due to glaucoma can damage your optic nerve, causing partial or total loss of vision.

How Your Brain Helps You See

The visual cortex in the brain's occipital lobe serves as the vision command center. The cortex processes and stores images and helps you make sense of what you see. Thanks to your brain, you can recognize faces, colors, letters, and shapes. You can also see fine details, avoid obstacles, keep your balance, predict the speed of moving objects, remember the things you've seen in the past, and easily recall information after reading it.

Your brain also controls the muscles that move your eyes and turns the slightly different information received from each of your eyes into one clear image.

If a stroke, tumor, infection, disease, or head trauma injures the brain, your vision and your ability to understand what you see can be temporarily or permanently affected.

Annual visits to the optometrist help you ensure that every part of your visual system is working properly. Contact our office if you're ready to schedule your next eye exam.

Sources:

American Optometric Association: Adult Vision: 41 - 60 Years of Age

National Eye Institute: How the Eyes Work

American Optometric Association: How Your Eyes Work

American Macular Degeneration Foundation: How the Eye Works as a Camera

American Academy of Ophthalmology: Eye Anatomy: Parts of the Eye and How We See, 3/9/21

Testimonials

Reviews From Our Satisfied Patients

  • I have been seeing Dr. William Berk for the last 20 years and have always received top notch service. Highly recommend Dr. Bill and his wife Dr. Anne Berk.

    - July 26, 2022
  • dr. anne is the best! she is really caring, professional, and hilarious. not many can make an eye exam enjoyable, but she and her staff are successful! :)

    - June 9, 2020
  • Love Dr. Anne! She is fantastic and so helpful figuring out solutions for seeing well in all areas of life! Thank you! Also staff is friendly and caring and was super happy to have photos instead of dilation and no more air puffs for eye pressure! State of the art!

    - September 22, 2022
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    - January 14, 2023
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    - October 27, 2022
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    - August 27, 2022
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    - January 15, 2023
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    - January 26, 2023
  • I really love all the people at HV Vision Source! The doctors listen to any questions or concerns I have & never give up on helping me. Thanks so much❣️

    - January 28, 2023
  • My Happy Valley Vision Source appointment went well. Dr. Chan was very helpful and informative regarding my vision requirements. I recommend them if you need eye care.

    - May 19, 2023
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    - March 10, 2023
  • The doctor and staff were great. Very knowledgeable and willing to answer all my questions and help me select a new pair of glasses. Thank you for the great service.

    - March 18, 2023
  • I arrived early. Only waited about 5 minutes. I ❤️ Dr.Nguyen. She's like a breath of fresh air. She diagnosed my issue quickly and I'm on the road to recovery! Thank you!😊

    - July 5, 2023
  • Completed my eye exam within an hour and everyone there is nice. Probably the best office I have been to throughout my life having glasses.

    - May 11, 2023
  • Wonderful experience, and very helpful getting my vision back to perfect.

    - June 9, 2023
  • I had the best experience here! I would recommend Happy Valley Vision Source to anyone looking for a new place to have an eye exam. I love my glasses and contacts and the staff was amazing!

    - May 23, 2023

Hours of Operation

Due to appointment demand, you may be charged a minimum $39 fee if you cancel or miss your appointment without 24 hour notice.

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Monday

9:00 am - 5:00 pm

Tuesday

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Wednesday

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Thursday

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Friday

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Saturday

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Sunday

Closed

Office Hours

Monday
9:00 am - 5:00 pm
Tuesday
9:00 am - 5:00 pm
Wednesday
9:00 am - 5:00 pm
Thursday
9:00 am - 5:00 pm
Friday
9:00 am - 5:00 pm
Saturday
9:00 am - 5:00 pm
Sunday
Closed

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