Contact lenses can cause headaches immediately after being fitted, later on, or when changing to hybrids. The wrong prescription that is too weak, too strong, or incorrect can lead to headaches. If poorly fitted, contact lenses can also begin to dry out after wearing them for some hours, leading to headaches. Dry eyes can sometimes cause headaches when they cause the wearer to squint from light sensitivity. Headaches can also result from computer vision syndrome when contacts dry out during computer work. Toric contact lenses can cause headaches due to the curved surface design. Additionally, headaches can arise from wearing cosmetic contact lenses, especially when dispensed without a prescription from an optometrist.