Provide a valuable resource to your clients or customers by linking to this resource page. Just place the following link on your website.
A cortical cataract is a clouding of the eye's lens that starts on the outer edge. This part of the lens is called the cortex. The cataract often looks like white, wedge-shaped streaks or spokes that point from the outside of the lens toward the center. Over time, these streaks can grow and affect your vision.
read more about a cortical cataract ...A common early symptom of a cortical cataract is glare. You may have trouble with the headlights of oncoming cars at night or find bright sunlight uncomfortable. As the cataract grows, it can cause blurry vision, difficulty seeing contrast between similar shades, and general light sensitivity.
Aging is the number one cause of cortical cataracts. As you get older, the proteins inside your eye's lens can change and clump together, creating a cloudy area. Other things that increase your risk include having diabetes, long-term sun exposure without UV protection, and smoking.
In the early stages, you may be able to manage the symptoms with new glasses or by using anti-glare sunglasses. When the cataract begins to seriously affect your daily life, your eye doctor will likely recommend surgery. Cataract surgery is a safe procedure where the cloudy lens is removed and replaced with a clear, artificial lens.
Cortical cataracts have a distinct growth pattern that differs from other types. They begin as wedge-shaped opacities at the periphery of the lens, resembling the spokes of a bicycle wheel. In the early stages, these spokes may not block light from entering the pupil, meaning vision remains clear. However, as the condition progresses, the spokes extend inward toward the center (axis) of the eye, eventually crossing the visual axis and obstructing sight.
Because cortical cataracts form on the outer edges of the lens, they cause specific problems when the pupil dilates. In low light or at night, your pupil opens wide to let more light in. This exposes the cloudy "spokes" that are usually hidden by the iris during the day. When light from streetlamps or headlights hits these ridges, it scatters uncontrollably, causing severe glare and "starburst" patterns that can make night driving hazardous.
The main difference is where it forms. Nuclear cataracts form in the center of the lens, while cortical cataracts form on the edge. This location is what causes the unique symptom of glare early on.
You cannot completely prevent them, but you can lower your risk. Ways to protect your eyes include wearing sunglasses that block UV rays, keeping health conditions like diabetes under control, and not smoking.
They usually develop slowly over many years. Your eye doctor will monitor its growth during your regular eye exams.
You should schedule an exam with your eye doctor if you notice any vision changes. Be sure to mention if you have new problems with glare, light sensitivity, or blurry vision. Regular eye checkups, especially after age 50, are the best way to catch cataracts and other eye conditions early.
1. Cataracts. National Eye Institute. https://www.nei.nih.gov/eye-health-information/eye-conditions-and-diseases/cataracts. November 26, 2025.
2. Cataracts - Symptoms and causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790. March 14, 2026.
3. Cataract - adult. MedlinePlus Medical Encyclopedia. https://medlineplus.gov/ency/article/001001.htm. August 4, 2023.
4. Cataract in the Adult Eye Preferred Practice Pattern. American Academy of Ophthalmology. https://www.aao.org/Assets/1d1ddbad-c41c-43fc-b5d3-3724fadc5434/637723154868200000/cataract-in-the-adult-eye-ppp-pdf. October 13, 2021.
5. Cataract Surgery. MedlinePlus. https://medlineplus.gov/cataract.html. November 25, 2025.