The crystalline is a transparent lens in the form of a small button bulging on both sides and is located immediately behind the pupil and iris, when its contents are opaque, it gives rise to what is known as a cataract which prevents the passage of light causing difficulty of vision and blindness.
The nuclear sclerosis of the crystalline happens to all dogs as they reach the age of 7 years. Due to an increase of its density it appears as a whitish opalescence that is accentuated more to the center; The opacity may be confused with a cataract due to its clinical aspect, but the great difference lies in that nuclear sclerosis only diminishes vision very slightly.
This is a normal change caused by the natural effect of aging and it is due to the fact that the internal fibers as layers that were formed through the lifespan of the pet, are now migrating and compressing towards the center.
