@misc{indiciae9c52458c5253,
  title = {Visual impairment: facing possible blindness.},
  author = {C J Heppen and S B Petersen},
  year = {1979},
  doi = {10.1300/j010v05n01\_05},
  url = {https://pubmed.ncbi.nlm.nih.gov/515889/},
  note = {Source identifier: 515889}
}