Modul BPJS Kesehatan https://www.bpjs-kesehatan.go.id/bpjs/application/modules/post/files/EBOOK_Panduan_Layanan_JKN_KIS_Tahun_2018.pdf diakses 21 Desember 2020Mayo Clinic https://www.mayoclinic.org/tests-procedures/eye-exam/about/pac-20384655 diakses 21 Desember 2020Science Daily https://www.sciencedaily.com/terms/eye_examination.htm diakses 21 Desember 2020Cigna https://www.cigna.com/individuals-families/health-wellness/what-happens-during-an-eye-exam diakses 21 Desember 2020American Academy of Ophthalmology https://www.aao.org/eye-health/tips-prevention/eye-exams-101 diakses 21 Desember 2020