The definitions, abbreviations, and acronyms in this section apply throughout this chapter unless the context clearly requires otherwise.

(1) "AAPOS" or "American Association for Pediatric Ophthalmology and Strabismus" means the national organization that advances the quality of children's eye care, supports the training of pediatric ophthalmologists, supports research activities in pediatric ophthalmology, and advances the care of adults with strabismus.

(2) "Crowding bars" means four individual lines surrounding a single optotype.

(3) "Crowding box" or "surround box" means crowding bars on all four sides extended to form a crowding rectangle surrounding a single line of optotypes.

(4) "Distance vision" means the ability of the eye to see images clearly at a calibrated distance.

(5) "HOTV letters" means a test using the letters H, O, T, and V calibrated of a certain size used to assess visual acuity.

(6) "Instrument-based vision screening device" means a U.S. Food and Drug Administration approved instrument for vision screening that uses automated technology to provide information about amblyopia and reduced-vision risk factors such as estimates of refractive error and eye misalignment.

(7) "Lay person" means any individual who is conducting school-based vision screening other than a school nurse, a school principal or his or her designee, a licensed vision care professional, or an individual trained by and conducting vision screening on behalf of a nationally recognized service organization that utilizes a test-retest protocol for vision screening. This includes, but is not limited to, retired nurses, nursing students, parents, and school staff.

(8) "LEA vision test(s)" means a test used to measure visual acuity using specific symbols or numbers, designed for those who do not know how to read the letters of the alphabet.

(9) "Licensed vision care professional" means a licensed ophthalmologist or licensed optometrist.

(10) "Near vision acuity" means the ability of the human eye to see objects with clarity at close range, also termed near point acuity or near acuity.

(11) "Optotype" means figures, numbers or letters of different sizes used in testing visual acuity.

(12) "Principal's designee" means a public health nurse, special educator, teacher or administrator designated by the school principal and responsible for supervision, training, reporting and referral of vision screening in instances where the school nurse or school principal is not filling this role.

(13) "School nurse" means a registered nurse acting as the health professional in a school whose specialized practice and attendant tasks and activities advance student health, well-being and achievement; and conforms to Washington state educational and nursing laws according to chapters 18.79 RCW and 246-840 WAC, and WAC 181-79A-223.

(14) "Sloan letters" means a test using ten specially formed letters which include C, D, H, K, N, O, R, S, V and Z to assess visual acuity.

(15) "Test-retest protocol" means a method of screening where a screener conducts two or more screenings for any student who meets the referral criteria in order to ensure the reliability of the initial screening.

(16) "Visual acuity" refers to the ability of the visual system to discern fine distinctions in the environment as measured with printed or projected visual stimuli.