How Your Eye Lens Works
The initial step in our vision begins with light passing through the cornea where 65% to 75% is "pre-focused" before it even reaches the lens.
Our eye's lens is a transparent, crystalline structure that, like glasses, directs incoming light to the back of the eye (the retina). The lens is not solid, but is formed of long transparent cells packed together in tight layers. These fibers are crystallins, water-soluble proteins that comprise 90% of the protein in the lens.
The lens is contained within a flexible capsule or sac composed of collagen. (During cataract surgery the lens is removed from this sac and replaced by an artificial lens). The lens is suspended in place from tiny ciliary muscles by hundreds of fine ligaments called zonules. The ciliary muscles adjust the lens to enable us to see near, middle and far distances clearly by relaxing to see distant objects and contracting to see objects near at hand. The amount of light that strikes the lens is regulated by the outer iris which contracts the central pupil size in bright light and expands it in dim light.
Light, focused according to the distance of the object, passes through the lens to the retina where photoreceptor cells in the retina direct the light energy to the optic nerve which, in turn, transmits the information to the brain for interpretation.
The lens can change as we age and be damaged in several ways. The most common is that with age it becomes less flexible and less ableto adjust between near and far distances. The lens can become clouded, obscuring vision. Damage to the eye's lens impairs vision for driving, close work, color and depth perception. Many other eye conditions and specific medications can lead to lens damage. Patients with impaired lenses may experience blurry or cloudy vision, poor night vision, difficulty in depth and color perception and other symptoms.
Causes of Lens Damage
Read the explaination from new research about the mechanics of exactly how and why the lens can become cloudy.
Many factors can bring about damage to the lens, including:
- Free radicals cause oxidation, in turn causing eye lens aging with consequent loss of flexibility and focusing ability.
- Chronic physical stress increases tension and tightness in muscles in general, including those supporting the lens.
- Food sensitivities or allergies may have the effect of causing congestion and impairing drainage which restricts nutrients from reaching the eyes.
- Toxins and side effects of pharmaceutical drugs. See drugs that harm the eyes
- Smoking raises the risk of lens damage, robbing the body of vitamin C, impacting blood circulation, and limiting blood circulation to the eyes.
- Diseases such as diabetes often result in side effects such as damage to the eye's lens due to the build-up of sugar resulting glycation (binding of sugar and protein molecules together).
- Poor digestion and nutrition give rise to nutritional deficiencies which contribute to lens damage.
- Heredity and advanced age by themselves are risk factors.
- Sunlight includes invisible UV and blue light that can cause damage to the lens by producing free radicals. These effects are cumulative overtime, particularly as we age in our ability to neutralize free radicals.