A systematic review on ‘Foveal Crowding’ in visually impaired children and perceptual learning as a method to reduce Crowding

Table 2 Inclusion criteria

Population	Children with Normal Vision up to 18 years
	Children and Adults with Visual Impairment
	Children with Cerebral Visual Impairment up to 18 years
	Adults with amblyopia (addressed for 2 intervention studies)
Intervention	Progress on crowding tasks after Perceptual Learning intervention (n=7)
Type of study	Randomized controlled trials (n=0)
	Non-randomized intervention studies (n=4)
	Cohort studies (n=3)
	Case - control studies (n=4)
	Cross - sectional studies (n=11)
Outcome measurements	Contour interaction area (n=7)
	Crowding ratio (n=8)
	Effects of Perceptual Learning on crowding (n=7)

ISSN: 1471-2415