The cataract linked to old age is known as senile cataract and usually appears after 60-65 years of age. The senile cataract can appear in one eye only or in both eyes and develop with a very variable speed between the two eyes and from individual to individual. Other than other types of cataract, the senile cataract progresses gradually over time but the speed of its evolution cannot be exactly predicted. It is appropriate to remember that the cataract is not a condition that can be transmitted from one eye to the other ort from person to person. No pharmacological remedies, eye drops, eye exercises or lenses that can slow-down, block or cause the regression of the process related to the loss of transparency of the lens. However, it is true that protecting the eyes from the UV rays by regularly wearing, since very young age, sunglasses or clip-on filtered lenses can help to prevent or delay the process that leads to the formation of the cataract in older age.
The senile cataract can have several stages of evolution. At the initial stage (incipient) the cataract is often asymptomatic. In some cases, however, the lens can be subject to a variation in the refraction index, which determines the appearance of refractive defects, such as light hypermetropia or a generally progressive shortsightedness (index myopia). In these cases the prescription of eye glasses can be sufficient to solve the problem. As the cataract progresses, a few additional symptoms appear such as blurring of vision, faded vision, altered perception of colors, loss of contrast, increased sensibility to light, glare, difficulty in the night vision, need of a better lighting while reading, double image while viewing. Such symptoms worsen over time together with the cataract. At a more advanced stage (brunescent), the opacification degree of the lens becomes such as to determine a significant impediment to the passage of the light to the inside of the eye, which can further evolve (black cataract) and determine a condition of real blindness.
The instrumental tests that are necessary during an in-depth eye examination in order to diagnose and, should it be the case, determine the right time for submitting to a cataract surgery are: the IOL Master that provides several anatomic parameters such as the length of the eyeball and the depth of the anterior chamber (i.e. the distance between the cornea and the lens), which can be accessed with surgical instruments during surgery; the Pentacam (topography, pachimetry, no-contact biometry) which measures the thickness, curvature of the cornea and the angular anatomic structure, the A-scan Ultrasonography that is useful to evaluate the size and hardness of the lens, the high resolution Optical Coherence Tomography (OCT) that analyzes each individual retinal layer in order to see whether there are retinal pathologies before the surgery, which might cause complications in the after-surgery time because of an inflammatory effect linked to its execution, and finally the B-Scan Ultrasonography, which shows whether the lens is well positioned and adherens for all the 360° of the suspending apparatus (zonula) of the ciliary body and whether any retinal tractions exist at the time of the surgery, such as to represent an ancillary risk factor.