What causes red eye? How to avoid it? In many old photographs we can see people with red eyes. Nowadays, this effect does not appear so often. However, this is not a result of lack of sleep or some kind of disease, although its occurrence in only one eye may indicate serious problems.
What causes red eye? It all depends on physics
Our eyesight adapts dynamically to lighting conditions. Regulates the size of the pupils depending on the available amount of light. In bright conditions, i.e. during the day or in a well-lit room, the pupils are constricted. In low light conditions, such as at night or in places with limited light, the pupils dilate to allow more light into the eye. In such conditions, when strong light from the flash reaches the eye and the subject looks directly into the lens, the photo often shows a red eye.
The light entering the pupil of the eye is almost entirely absorbed by the blood-supplied part of the eye’s interior. Part of the spectrum with a frequency corresponding to the red color is reflected (the retina is very vascularized), which sometimes gives the effect of “red eyes”
– we read on the Integrated Educational Platform of the Ministry of Education and Science, where free learning materials are posted. Today, many cameras are equipped with a function that reduces the visibility of red eyes. Although the effect sometimes spoils the photo, researchers have a slightly different opinion.
Researchers explain the red eye effect. “It’s a good sign”
Red eye does not appear in every photo, but it should always appear symmetrically.
This is usually a good sign that the retinas in both eyes are unblocked and healthy
– emphasized specialists from . The problem occurs when the effect is visible only in one eye, occurs asymmetrically, or when one of the pupils is not red but appears white or yellow. As American doctors warned, this may be a sign of health problems. When only one eye is red, or the red in one eye appears less intense, this may be a sign of strabismus in children. White reflexes may signal more serious problems, such as cataracts, retinal detachment and infections in one of the eyes. It may also be one of the symptoms of retinoblastoma, a rare malignant tumor in children. In turn, the yellow effect may indicate congenital and progressive damage to the retinal blood vessels.
How to eliminate the red eye effect? Use this clever method
Modern digital cameras often come with advanced features such as automatic red-eye reduction. This feature works by removing unwanted effects on your photos and automatically correcting them before you save the photo. However, if we want to make sure that we do not encounter bloody pupils when viewing the photo, we can do a few things:
- avoid looking directly at the flash;
- reduce flash brightness;
- use outdoor natural lighting.
Source: Gazeta
Bruce is a talented author and journalist with a passion for entertainment . He currently works as a writer at the 247 News Agency, where he has established himself as a respected voice in the industry.
