Participant demographics across review studies (non-experimental)
| Author (year, country) | Sample size | Mean age | Gender | Nationality (ethnicity) | Vision impairments |
| Salas and Gonzalez (1988, USA)61 | 1 | 4 years | Female | American/Italian | Bilateral optic atrophy |
| Rogow (1982, Canada)65 | 10 | 4 years | 6 Females 4 Males | Canadian (Chinese) | Anophthalmia, cortical blindness, partial sight impairment, several sight impaired and total blindness |
| Shoemark (1991, Australia)62 | 1 | 8 years | Male | Australian | Detached retina (blind) |
| Silliman et al (1994, USA)66 | 1 | 10 years | Male | American | Blind |
| Kern and Wolery (2001, USA)63 | 1 | 3 years | Male | American (African) | Bilateral congenital anophthalmia/microphthalmia |
| Villasenor and Vargas-Colon (2012, USA)67 | 2 | 14.5 years | 1 Female 1 Male | American | Retinopathy of prematurity |
| Desrochers et al (2014, USA)68 | 1 | 13 years | Female | American | Bilateral congenital anophthalmia |
| Metell (2015, Norway)64 | 10 | 2.5 years | 5 Females 5 Males | Brazilian | Optic nerve atrophy, septo-optic dysplasia, chorioretinitis, coloboma of optic papilla, chorioretinitis, microphthalmia, corectopia-clara, optic nerve atrophy, toxoplasmosis, agenesis ocular, optic nerve atrophy, anophthalmia |
| Villas Boas et al (2016, Brazil)69 | 1 | 5 years | Male | South American | Nystagmus and blind |