Understanding the Human Eye: How It Works

Most people go throughout their day being constantly bombarded with visual input, yet never stop to think about the amazing transformation this information must go through in order to be processed by the brain. None of it would be possible without one of the most complex organs in the body: the human eye. Through research in the field of optometry, people today have a much more accurate understanding of how this process works.

Understanding How the Eye Works 

First, light travels through the cornea, which is the clear covering over the eye that acts as a window. The cornea bends the light, allowing it to pass through the narrow pupil. A lens behind the iris helps to either shorten or lengthen the light rays to ensure that the image is focused. The retina lies at the back of the eye. The light rays come to a point at the retina, which receives the crystal-clear image in its network of nerve cells, then transmits it to the optic nerve. The optic nerve carries the image to the brain. The most amazing part of this process is that it happens at lightning speed, over and over again throughout the day.

How to Care for the Eyes

With these incredible organs working overtime, it's important to take good care of them. The most important step in taking care of the eyes is scheduling regular checkups with an optometrist. This will help determine if there are any ongoing issues, and can hopefully help to detect issues early before they become more serious.

The eyes require certain nutrients to keep them healthy between checkups, so eating a well-balanced diet will help keep them healthy. Protecting the eyes from damage is also important. Sunglasses can help protect the eyes from the harmful UV rays found in sunlight, and safety glasses should be worn in hazardous conditions. Thanks to the wonders of optometry, the eyes can continue to process countless messages per day, all without people ever noticing. To keep your eyes healthy longer, contact Excellent Vision in Portsmouth today.

How Blue Light Damages the Eyes

Blue light is visible, high-energy light that increases memory, cognitive function, and alertness. By regulating the natural circadian rhythm of sleep and wakefulness cycles, blue light helps control the mood, memory, and hormonal balance of an individual.

Threats of Increasing Blue Light

About 30 percent of all visible light is high-energy visible (HEV) or "blue" light. While the primary source of blue light is the sun, experts in optometry express concerns about the rapid increase of manufactured blue light. Fluorescent and LED lights transmit significant levels of blue light, as do the screens of TVs, computers, smartphones, electronic notebooks, and other digital devices. In today's modern workforce, approximately 60 percent of people spend more than six hours a day in front of a digital device, which significantly increases exposure to blue light.

Dangers of Blue Light

Staring at screens all day and night creates unfocused visible "noise" that reduces contrast and leads to digital eye strain. Also, excess reading on a tablet computer at bedtime can disrupt the sleep cycle, leading to daytime fatigue. As a result, the cumulative effect of rising exposure to blue light indoors can damage the retina's light-sensitive cells, causing cataracts, and increasing the risks of macular degeneration. In fact, 70 percent of adults who regularly use media devices have reported symptoms of digital eye strain.

Schedule an appointment with an optometrist to discuss the type of filters or glasses best suited for protecting eyes against the threats and dangers of blue light.