Nearsightedness - Myopia
Nearsightedness or Myopia is very common; 25% of adults worldwide live with this vision defect. For these people close objects are clear, but distant object are blurred and difficult to distinguish. Nearsightedness happens when light has to focus in front of the retina, as opposed to on the retina, because of the eye's unusually long shape. Passed on genetically, the condition is often detected between the ages of 8 and 12 years old. Nearsightedness worsens during adolescence, and stabilizes in early adulthood. Although most often benign, nearsightedness when very severe implies a higher risk of detached retina.
Farsightedness - Hyperopia
Farsightedness or Hyperopia occurs when light has to focus behind the retina, as opposed to on the retina, because of the eye's unusually short shape. Farsighted people have blurred vision at all distances, and often suffer from headaches and eye fatigue, as they make a constant effort to focus. The condition is usually passed on genetically, and young children often are slightly farsighted if only temporarily. In most cases, the condition corrects itself as their eyes naturally grow in length. However, some, who remain farsighted and have enough focusing flexibility to fight the blur, are unaware of their condition.
The eye lens starts out soft and flexible, and readily changes shape to focus. But as people get older, the lens gradually hardens, and has increasing difficulty to focus. Presbyopia is not to be confused with farsightedness. Unlike farsightedness, which causes blurred vision at all distances, presbyopia only affects close vision.
Astigmatism affects the outer layer of the eye, called the cornea. It means that the curvature of the cornea is too severe, leading to a distorted vision of both near and far objects. Images are blurred because some of the light rays are focused and others are not. Astigmatism is a genetically inherited condition, and sometimes occurs in combination with nearsightedness or farsightedness.
BLUE LIGHT & UV RAYS
New Eyeglass Lenses Block Harmful Blue Light and UV Rays
By selectively blocking harmful blue light and ultraviolet rays, Crizal® Prevencia™ No-Glare lenses help prevent the early occurrence of certain eye impairments and diseases.
What is Blue Light and Ultraviolet Light?
Blue light is part of the visible light spectrum and is emitted by the sun and artificial light sources such as LEDs, computers, and smart phones. Some types of blue light can be beneficial and help regulate our bodies’ internal biological clocks. However, blue-violet light can have a harmful impact on the eyes, specifically the retina. It is also a risk factor for the onset of age-related macular degeneration, a deterioration of the part of the retina responsible for sharp, central vision.
Ultraviolet light not only affects the skin by increasing the risk of skin cancer, it can also be dangerous for the eyes. Excessive exposure to UV light without proper protection can lead to cataracts. It can also cause a sunburn on the cornea of the eye (known as photokeratitis), which can lead to temporary blindness.
How It Works
Since some forms of blue light are necessary, Crizal Prevencia No-Glare lenses selectively block only the harmful types of blue light. New technology called Light Scan™ allows beneficial blue light to pass through the lens while filtering out the dangerous blue-violet light that can cause age-related macular degeneration.
Crizal Prevencia No-Glare lenses also offer comprehensive UV protection.
Do You Need Protection against Blue and UV Lights?
Blue light is emitted by a plethora of electronic devices including cell phones, tablets, and laptop computers. A recent study found that Americans devote more than 10 hours a day to screen time, meaning protection against blue light is important for anyone using a digital device on a regular basis. Another source of blue light is energy efficient technology in the form of fluorescent light bulbs and LED lights. Most offices and stores use fluorescent light bulbs, thus putting your eyes at risk if unprotected.
It’s important to protect your eyes against UV exposure both indoors and out. Our eyes are exposed to UV radiation 365 days a year, even on cloudy days. In fact, up to 40% of UV exposure occurs when we aren’t in full sunlight. Crizal Prevencia No-Glare lenses protect your eyes against UV rays from the sun, but also from UV rays that can travel indoors through windows. This is especially dangerous for people who spend a lot of time in their car or near windows in their home or office.
Since most people are at risk for overexposure to both blue light and UV light on a daily basis, it’s important to talk your eye doctor about Crizal Prevencia No-Glare lenses that can protect your eyes from harmful blue light and ultraviolet light.