What is the crystalline lens?

What is the crystalline lens?

You may be familiar with contact lenses, but did you know that we are born with a similar structure inside our eyes? The crystalline lens is the natural lens located behind the iris, or the coloured part of the eye. Similar to a contact lens, this clear structure helps focus light rays onto the retina. Muscles attached to the lens contract or expand the lens to help us see at near and far distances.

schema cataract


What is a refractive error?

Sometimes the cornea (the clear structure in front of the iris) and/or the lens do not focus light rays directly onto the retina. When this transfer of light waves does not occur properly, that is, the refraction does not occur properly, you have a refractive error. Examples of refractive error caused by the cornea or an irregularly-shaped eye include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism.

When light does not pass properly through the lens, it is usually caused by certain conditions that affect the structure or clarity of the lens.

What conditions affect the lens?

There are generally two categories of conditions that affect the lens: those that affect its elasticity, and those that affect its clarity. These conditions usually occur naturally as we age. Progressive lens dysfunction is the term used to describe the progression of these natural conditions.

When we reach our 40s, the crystalline lens’ elasticity begins to decrease. Typically, we can still see clearly at a distance, but the muscles attached to the lens lose their ability to return the lens to its rounded shape, making it difficult to see up-close. This condition is known as presbyopia.

Later in life, usually in one’s 70s, cataracts may begin to form. Cataracts make the lenses opaque, making vision blurry, making colours less sharp and they can even cause vision loss in later stages if they are left untreated.

Lens treatment options

There are two main treatment options available for a dysfunctional lens, other than temporary fixes like reading glasses. These are:

  • Lens PresbyVision™: a surgeon will replace your eye’s natural lens with an artificial one that allows you to, once again, see at all distances. The added benefit of this is that cataracts will not be able to form on the artificial lens down the road.
  • Cataract surgery: the main difference between cataract surgery and other lens replacement procedures is that in cataract surgery, the natural lens is cloudy when it needs to be replaced. There are several lens options available should the patient also need to correct a refractive error or to help with presbyopia.

If you’re interested in learning more about our lens-replacement or other vision correction procedures, book your free, no-obligation consultation today!