Lazy eye treatment for adults: what the research shows

Is it too late?

Official guidance puts the emphasis on early treatment. The NHS says treatment should ideally start before age 7 [15], and the AAO advises treating before age 7 or 8 [16]. The National Eye Institute adds that treatment is usually less effective in adults than in children [1].

For a long time, many people assumed the visual brain stops changing after childhood. Research has moved on. A 2013 laboratory study started from the view that the adult visual cortex keeps a significant degree of plasticity. It found that reducing suppression with dichoptic presentation produced more plasticity than forced use of the amblyopic eye alone [11]. A 2014 review said that new treatments aimed at suppression appear to improve visual function, even in adults, on the basis of early data [12]. A 2009 review of perceptual learning, which means practising a visual task, concluded that practice can give a long-lasting improvement in the amblyopic eye [13].

So the honest answer is: adults can sometimes improve, but gains are smaller and less certain than in young children.

What studies of adults found

A meta-analysis of newer methods

A 2015 meta-analysis pooled 24 studies of newer behavioural treatments in adults with amblyopia. These included dichoptic training, perceptual learning and video games. On average, acuity improved by 0.17 logMAR, which is about 1.7 lines on an eye chart. About one in three participants (32%) gained 0.2 logMAR or more. Depth perception improved by at least two steps in 42% of participants. People with more severe amblyopia gained more acuity, and the vision at the start of treatment was the strongest predictor of the result [21].

A small headset study

One preliminary study enrolled 17 adults aged 17 to 69 with anisometropic amblyopia. They did 8 sessions of 40 minutes with a dichoptic game in a virtual reality headset. Average acuity in the weaker eye improved from 0.58 to 0.43 logMAR [23]. The study was small and early, so it can only suggest what might be possible.

A small randomised trial with mixed results

A randomised, double-masked trial tested a virtual reality prototype in 20 people aged 7 to 38, whose earlier treatment had failed. Acuity did not change meaningfully in the treated group (0.49 logMAR at 16 weeks, against 0.47 at the start). Depth perception did improve at 8 weeks [25]. This shows why one small study is not the last word.

Older children and teenagers

A large trial of children aged 7 to 17 gives some guide. Among 7 to 12 year olds, 53% who had patching, close-up activities and atropine improved by two or more lines, compared with 25% who had glasses alone. Among 13 to 17 year olds, patching may have helped when amblyopia had not been treated before, but it seemed to help little if patching had already been tried [18].

What to expect

• Results vary. Some people gain a few lines. Others gain little or nothing.
• Studies are small. Most of the adult studies have few participants and short follow-up.
• Acuity and depth perception can change differently. One can improve without the other.
• Treat the cause first. An eye exam can check for problems that glasses, or surgery for a cataract, might help. Treatment for the cause comes before anything else [1][16].
• Consistency matters. Short, regular sessions are easier to keep up than long, occasional ones.

Stop and see an eye care professional if you get headaches, eye strain that does not settle, or double vision.

Questions to ask your eye doctor

• Is my amblyopia still linked to a cause that can be treated?
• What improvement, if any, is realistic for me?
• Which options do you suggest for an adult, and what evidence is there for them?
• How will we measure progress, and when will we decide whether to continue?

About ZyncView

ZyncView is a separate product from anything described on this page. It is a set of free browser games and a reading exercise for vision training and eye coordination, played with red/blue glasses. It is a wellness and entertainment product. It is not a medical device, it is not a treatment for lazy eye or any other condition, and it has not been tested in a published trial. If you are worried about your vision or your child's, see an eye care professional first. You can try the games or read how dichoptic games work.