Tip:
Highlight text to annotate it
X
Hello, and welcome to HealthiNation, I’m Malachy Cleary.
Our sight is often the first, and sometimes the most important way we gather information
from the world around us. It’s the way most of us recognize people we know, or safely
cross a street. But, when you have problems with your sight,
the world around us becomes a blurry, dark, even confusing place. There are a lot of reasons
why you may have problems seeing. Some are common, and can be easily fixed. But we also
hear of more serious conditions like glaucoma, and macular degeneration.
Let’s hear from Dr. Roshini Raj about how the eyes work.
To understand how the eyes work, it’s helpful to compare the eyes to a camera. Cameras use
a lens and film to produce an image, and in a way, so do the eyes.
It’s normal to have changes in vision. It can happen when you’re in grade school,
or as we age. But sometimes these changes can be signs of conditions that can cause
severe vision loss or even blindness. And these need special attention.
Let’s take a closer look to better understand what healthy vision means.
Light comes in through the cornea, a clear tissue that covers the front of your eye.
The pupil is the dark spot in the middle of your eye. It works like a camera shutter,
controlling the amount of light that enters our eyes. When it’s dark, the pupil dilates,
or widens; when it’s bright, the pupil gets smaller. Surrounding the pupil is the iris,
this is the colored ring of muscle fibers that help the pupil change size.
When you look at an object, light rays enter your eyes. These light rays are bent and
focused by the cornea, lens, and vitreous, that’s the clear jelly-like fluid that fills
the inside of your eye. The lens' job is to make sure the rays come to a sharp focus on
the retina at the back of the eye. Think of the retina as the film in the camera. It’s
lined with light-sensitive cells, called photoreceptors, that capture, upside-down, the images in our
visual field. The sensitive macula, critical for sharp focus, is the most active part of
the retina. A healthy macula helps us read small print and see the images in our direct
line of vision. When light rays reach the retina, they’re converted into electrical
pulses that travel through the optic nerve to your brain, there, the image then gets
flipped right-side up. Sometimes, problems with your eyes can be
fixed with glasses or contacts. That’s the case when the lens doesn’t focus light correctly
on the retina. If you can see well at a distance, but not
up close you may have farsightedness. If you can see objects that are close, but not far
away, you may have myopia, or nearsightedness. Most times farsightedness, and nearsightedness
can be or corrected. Unfortunately, blurred vision might mean more
than a change in the prescription of your glasses. It might be a sign of something that
warrants more attention, and you should see an eye doctor. There are two types of eye
specialists, ophthalmologists and optometrists. Ophthalmologists are certified medical doctors
who provide full eye care, including diagnosis and even surgery. Optometrists offer many
of the same services as ophthalmologists, but they might refer you to an ophthalmologist
for more complex eye problems.