What is it about ?
Sight is the work of the eyes, the brain and the nerves that connect them. Our eyes allow us to distinguish light, dark, colors and depth, but it is only in our brain that we can understand the meaning and can we recognize objects. Sight is an essential sense in our daily life.
Several elements are used to assess the view:
- THE’visual acuity reports how far or near a person can see. Visual acuity provides information on the size of the smallest digits that a person can recognize, near or far, during a classic eye exam.
- The contrast sensitivity helps tell how well a person can distinguish small differences in brightness (luminance) between neighboring surfaces. The faintest shadow a person can see represents the better contrast sensitivity.
- the field of view represents the area a person can see without moving their eyes.
- The color vision provides information on the differentiation of colors perceived by the person.
- In night vision, the distinction between light and dark is important. Among the photoreceptors of the inner layer of the retina are cones and rods. The cones work in daylight, while the sticks work in low light.
What can you do ?
See the doctor if you think you have problems with your eyesight.
If you suspect problems with a child, it is recommended to have it examined.
Additional examinations in a specialized center are necessary for babies when they cannot make eye contact by the age of 8 weeks at the latest.
How is the diagnosis made?
Sometimes the doctor actively examines the eye. But in most cases, he will refer to an ophthalmologist or an optometrist.
Visual acuity is measured using the smallest letters or numbers that a person can read at a given distance. For the measurement of near vision, we use the same card with letters. For children, the doctor will use a card with symbols.
Contrast sensitivity is measured using an optotype (grid) test in which the surfaces have different brightness. It is important for diabetics.
The doctor examines the field of vision, i.e. the area that a person can see without moving their head or eyes. He sits facing the patient and stares into her eyes. With his fingers, the doctor assesses the limits of the field of vision and thus compares his own field of vision with that of the patient. This examination can detect tubular vision. It is also possible to measure the field of vision with greater precision by using a device at the ophthalmologist. This device has a small ball attached to a thin stick that can be moved in several directions. The examined person sits in the center of the field, sits and looks straight ahead. She answers when and from which side she sees the ball. As with the finger test, the person being examined should not follow the movement of the fingers or the ball with their eyes. The eyes should remain focused on the midline.
Color vision can be examined using a test primarily focused on distinguishing between red and green hues. Specialized professionals carry out additional tests.
To test for night vision, the doctor examines how quickly the person’s eye can adapt to the dark.
Young children and babies with suspected sight problems are referred to a specialized center for further examinations.
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