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Lazy Eye in Adults: Causes, Signs & Options

A plain-English guide to amblyopia in adults: why it happens, how it's diagnosed, and the options adults have today.

Medically reviewed by: TBD — licensed OD/MD · Last reviewed: TBD

What is a lazy eye (amblyopia)?

Amblyopia, often called "lazy eye," is reduced vision in one eye (sometimes both) that develops because the brain and that eye didn't learn to work together properly in childhood. The eye itself may look healthy; the difference is in how the visual brain processes its signal. "Lazy eye" is also sometimes used for an eye that turns (strabismus), which is a related but different condition.

What causes a lazy eye in adults?

Amblyopia starts in childhood and can persist into adulthood. Common causes include:

  • Anisometropia — a prescription mismatch between the eyes, so one eye sends a blurrier image.
  • Strabismus — an eye that turns in, out, up or down.
  • Deprivation — something blocking vision early in life, such as a cataract.

Signs and how it's diagnosed

Adults may notice one eye seeing less clearly, difficulty with depth perception, or that they rely on one eye. But only a comprehensive eye exam by an optometrist or ophthalmologist can diagnose amblyopia — other eye diseases need to be ruled out first.

Options for adults

  • Glasses or contact lenses — correction comes first, and every trial we cite used it alongside training.9
  • Patching or blurring the stronger eye — the traditional childhood approach; discuss with your eye doctor.
  • Binocular / dichoptic training — two-eye training. Research suggests the adult visual brain can still improve: in a 24-study review, adults gained an average of 0.17 logMAR (about 1.7 chart lines) with structured visual training.1
  • In-office vision therapy — supervised programs offered by some optometrists.
  • Surgery — used to align the eyes in strabismus; it changes eye position rather than training the visual brain.

Can a lazy eye be improved in adults?

Research suggests yes, for some people — and it's worth being clear-eyed about the limits. Studies have reported improvements in 3D depth perception after dichoptic training,2,5 and in studies most gains were largely retained months after training ended.2,6 But the largest masked trial that included adults (BRAVO) found no benefit over a placebo game,8 and results vary widely.

Get the free research guide See the science

Individual results vary. Eyeletics is a wellness and training program, not a medical device, and does not diagnose or treat any disease.

Sources

  1. Tsirlin I, et al. (2015). Behavioral training as new treatment for adult amblyopia: a meta-analysis. PubMed 26114483
  2. Vedamurthy I, Levi DM, et al. (2015). A dichoptic custom-made action video game as a treatment for adult amblyopia. Vision Research. Europe PMC; Sci Rep 2015
  3. FDA De Novo DEN210005, Luminopia One (2021, children 4–7) FDA; indication expanded to ages 4 to <13 by 510(k) K243819 (cleared Apr 9, 2025) FDA
  4. FDA 510(k) K221375, CureSight (children 4 to <9, cleared Sep 29, 2022). FDA
  5. Li J, Hess RF, et al. (2013). Dichoptic training enables the adult amblyopic brain to learn. Current Biology. Cell
  6. Polat U, et al. (2004). Improving vision in adult amblyopia by perceptual learning. PNAS. PubMed 15096608
  7. Holmes JM, et al. (2016). PEDIG ATS18 binocular iPad treatment vs patching. JAMA Ophthalmology. JAMA
  8. Gao TY, et al. (2018). BRAVO randomized clinical trial. JAMA Ophthalmology. JAMA — the largest masked adult-inclusive trial: no benefit over a placebo game.
  9. All cited trials used optical correction (glasses) alongside training.

Last reviewed: TBD · Medically reviewed by: TBD — licensed OD/MD reviewer