What are Cataracts?
Cataract is nothing more than a clouding of the crystalline lens (the natural lens) inside of the eye. The crystalline lens is located immediately behind the iris (the colored part of the eye). When you look at your eye’s pupil in the mirror, you are looking directly at your crystalline lens. The darkness of the inside of the eye is what causes the pupil to look black. Even if you have a significant cataract, it is virtually impossible to see the cloudiness in the mirror.
There are many types of cataracts based on the age or circumstances of the individual, and the location of the clouding within the crystalline lens. Some people are born with cataracts, some are due to metabolic disease (Galactosemia, Diabetes), some are due to injury, and some are due to certain medications (Prednisone, Indomethacin). Radiation from cancer treatment and ultraviolet exposure from welding, or simply the sun, can cause cataracts.
Most cataracts are simply age-related. The crystalline lens’ clear proteins lose their elasticity naturally and by the time most people are in their early 40’s, they notice a decline in their ability to focus up close (see WHAT IS PRESBYOPIA). By around age 55, the crystalline lens has lost 100% of its flexibility, yet its clarity is still quite good. Over the remainder of one’s lifetime, the proteins of the crystalline lens slowly denature and become cloudy (much like how the crystal clear egg white turns snow white in the frying pan). This cloudiness will gradually cause the individual’s vision quality to diminish. By age 75, the average person will have a cataract that is affecting their ability see at least under certain circumstances. Needing more light to read, trouble seeing at night, glare and halos around headlights and streetlights, are some of the more common symptoms of cataracts. Later stage cataracts will cause blurry vision and significant vision loss.
Each individual has a different threshold of how much functional difficulty they will put up with due to cataracts before they seek help. We have had patients who still have 20/20 vision, but have trouble driving at night, that chose to do cataract surgery. Conversely, we have seen people with 20/50 or poorer vision that are happy as can be with their poor vision quality. Cataract surgery is the most commonly performed surgery in the modern world, and is also the most successful surgical procedure humans have ever developed.
Cataracts rarely ever “have to” be removed, but if the individual is struggling with their daily activities, then their reduction of quality of life dictates when they will choose to do surgery. People that still drive must have at least 20/40 vision to maintain their license in all 50 states. If cataracts are reducing the individual’s vision so that it is worse than 20/40, then they will be required to have surgery in order to continue to drive legally.
Cataracts are easy for the optometrist to see with the use of the slit-lamp biomicroscope during a routine eye exam. The optometrist will counsel the patient about their cataracts and help them to make the decision that is in their best interest. Whether surgery, or just the best pair of glasses and regular monitoring is the best treatment for them will be a decision made between the optometrist, the patient, and their family.