Low-order and high-order aberrations are types of optical imperfections in the eye that affect vision quality. Here’s a breakdown of each:
Low-Order Aberrations (LOAs):
These are common refractive errors that can be corrected with glasses, contact lenses, or basic refractive surgery (like LASIK).
Types:
Myopia (Nearsightedness): When the eye is too long or the cornea is too curved, causing distant objects to appear blurry.
Hyperopia (Farsightedness): When the eye is too short or the cornea is too flat, making near objects appear blurry.
Astigmatism: When the cornea or lens has an irregular shape, causing blurred or distorted vision at all distances.
Effect on vision: These errors can usually be corrected to 20/20 vision with standard corrective lenses.
High-Order Aberrations (HOAs):
These are more complex optical imperfections that cannot be fully corrected with glasses or standard contact lenses.
Types:
Coma: A distortion that causes light points (like stars) to appear smeared or stretched, often in a comet-like shape.
Spherical Aberration: Occurs when light rays entering the eye at different distances from the optical axis focus at different points, leading to blurry or distorted vision, especially in low-light conditions.
Trefoil, Tetrafoil, etc.: More complex distortions that affect visual clarity.
Effect on vision: These aberrations can cause halos, glare, starbursts, or reduced contrast sensitivity, particularly noticeable at night or in low-light conditions. They typically reduce the overall quality of vision even if the person has 20/20 visual acuity.
