Cataracts

Cataracts are opacifications in the lens of the eye, which sits directly behind our iris (the colored part of our eye). The lens is the structure that contracts and expands to help us focus far away and up close. Cataracts usually develop slowly over a matter of years, but some forms can develop more quickly than others. There are several forms of cataracts that can form. They are as follows:

Nuclear sclerosis (NS): yellowing and eventual browning of the innermost portion or “nucleus” of the lens^{1, 4}

Cortical cataract: wedge-shaped opacities that start at the edge of the lens and eventually move inward

Subcapsular cataract: occurs towards the front or back of the lens in the visual axis, usually forms more quickly than other types of cataracts¹

Congenital cataract (usually polar cataracts): central white opacities, can be genetic; removed as early as possible if affecting vision to prevent amblyopia (cataract can obstruct proper vision development and lead to permanent decreased vision depending on severity)⁵

Diabetic/”snowflake” cataract: appears as white opacitie,; occurs with uncontrolled blood sugar levels⁶

Traumatic cataract: occur as a result of injury, chemical burn, or radiation exposure; can develop quickly⁵

Polychromatic/“Christmas tree” cataract: pointed and reflective opacities of the lens, associated with myotonic dystrophy (muscular dystrophy that affects both muscles and organs)^{2, 3}

Cataracts can cause blurred or clouded vision, glare (especially at nighttime), alterations to colors, shadowing or double vision with each eye separately, the need for more direct light when reading, and sensitivity to light.¹

Cataracts are most commonly caused by age, but can also be caused by trauma, systemic disease (like diabetes or high blood pressure), infection, injury, systemic steroid use, or may be present at birth.¹

Cataracts are diagnosed with a dilated ophthalmic examination. An eye care practitioner can examine the cataracts present and determine which type of cataract(s) and how far along they are developed. The stage or grade of cataract progression can also be determined by a visual acuity measurement, which is a test that measures how well you can see.

Cataracts are treated with cataract extraction surgery. With this procedure, an ophthalmologist is able to remove the cloudy cataract and insert a clear intra-ocular implant (IOL). This is usually an outpatient procedure and is performed one eye at a time (a few weeks apart).

Cataracts are the leading cause of blindness in the world. Luckily, they are treatable with cataract extraction surgery.⁷

To slow the progression of cataracts, it’s important to wear sunglasses when outdoors, refrain from smoking, ensure adequate control of blood sugar, and eat a diet rich in nutrients and antioxidants.¹

1. https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790
2. https://www.mda.org/disease/myotonic-dystrophy#:~:text=Myotonic%20dystrophy%20(DM)%20is%20a,to%20relax%20muscles%20at%20will.
3. https://www.aao.org/eyenet/article/christmas-tree-cataract
4. http://www.med.umich.edu/1libr/Ophthalmology/Cornea/NuclearCataract.pdf
5. https://eyewiki.aao.org/Cataract
6. https://www.aao.org/image/diabeticsnowflake-cataract-2
7. https://www.light-for-the-world.org/causes-blindness