Frequently Asked Questions

March 2006

Developed by the Minnesota Department of Education, Minnesota Department of Health, and the Minnesota Department of Human Services.

Index of Questions

Vision Screening vs. Vision Examination

Question 1. Should children be screened or have total eye exams?

A. The American Academy of Ophthalmology (AAO), the American Academy of Pediatrics (AAP), the American Academy of Ophthalmology and Strabismus (AAPOS), Prevent Blindness America, U.S. Public Health Service, National Association of School Nurses (NASN), Head Start, Maternal and Child Health Bureau, Institute for Clinical Systems Integration (I.C.S.I), U.S. Preventative Task Force, and Bright Futures recommend vision screening. The recommendation is that all infants and children be screened for vision problems and any child who does not pass these screening tests should have further evaluation by an eye professional.

The eyes of a newborn should be examined for general eye health (including a red reflex) while in the nursery. If the newborn is high risk, then they should be examined by an ophthalmologist.

Question 2. When is a newborn or any other child considered high risk for potential vision problems?

A. Newborns or children considered high risk include:

  • Premature infants
  • Those with a family history of retinoblastoma, glaucoma, or cataracts in childhood, retinal dystrophy/degeneration or systemic diseases associated with eye problems
  • When any opacity of the ocular media is seen
  • If nystagmus is seen
  • Infants with neuro-developmental delay
  • Other children who should have an eye examination by an eye professional are those with a family history of strabismus, amblyopia and/or sensorineural hearing loss

Visual Acuity Screening

Question 3. There seem to be so many vision charts available, which charts are recommended in the Minnesota Vision Screening Guidelines for children under age 6?

A. Visual acuity screening in the schools is recommended for children participating in the Early Childhood Screening program and students in grades 1, 3, 5, 7, and 10. It is also recommended for transfer students, students receiving a special education evaluation, and upon parent, teacher or student request.

The 10 foot HOTV or the LEA chart with 50% spaced rectangle boxes around each line is the MDH recommendation for children ages 3-6. Good-Lite manufactures the charts; however, they are available through other distributors. Following are the MDH approved visual acuity charts. They are available from the vendors listed at the end of this section.

HOTV ChartHOTV Chart
Lea ChartLea Chart

Question 4. What is a 50% reduced rectangle eye chart?

A. In each rectangle on the new charts, the space below and above each letter to the edges of the rectangles is 50% of the letter's height. There is 100% spacing between each letter within the rectangle. This creates what is known as the crowding phenomenon. These charts are more sensitive to screening for potential amblyopia than are the old wide spaced charts.

Question 5. When charts have the bottom lines split into two columns, do you have to have the right eye read the left column and the left eye read the right column?

A. No. Each eye can be screened by having the child point to the symbols (HOTV or LEA) or read the letters using a different column for each eye or the same column.

Question 6. Are there any visual acuity charts available for children age 2 ½ to 3?

A. Yes, MDH recommends that you first attempt the LEA or HOTV charts listed in question #3 by having the child match the symbols or letters. It is also important to provide the young child with an adequate amount of time and encouragement to do the task. If the child is still unable to perform or complete the task, screen the child with the Minnesota Early Childhood Screening Flipchart available from vendors listed on the MDH website listed at the end of this document.

Early Childhood Screening Flipcharts by Goodlite and School HealthFlip Charts

Question 7. Are there tools available to help me prepare the child for screening?

A. There are other tools available to prepare very young children for vision screening, such as the Lea Puzzle. Young children will feel comfortable with the vision screening and will become familiar with the shapes used in the visual acuity charts by playing with the Lea Puzzle prior to the vision screening.

Lea PuzzleLea Puzzle

Question 8. Are there other visual acuity charts available for children age 6 years and under?

A. Yes, however, these charts have been less effective with some children, so these are only recommended for children who may have higher cognitive skills. Examples of these HOTV charts are below:

Proportional Chart #GL 600736Proportional Chart #GL 600736
Linear Chart #GL 600717Linear Chart #GL 600717

Question 9. What evaluative criterion was used in the development of the Vision Guidelines for these new vision acuity charts?

A. Chart selection was based on sensitivity, specificity, testability, optotypes, distance, the presence of a 20/25 line, practicality of use and cost, and cultural and disability bias. Various state and federal regulations for screening programs, as well as the federal Head Start Performance Standards, were also reviewed.

Other considerations included in the recommendations for the Vision Screening Guidelines were:

  • The 10-foot visual acuity charts should have the 10/12.5 line
  • The charts should not have symbols or optotypes (either letters or symbols) that require functions other than recognition of the optotypes. Some of these charts introduce language or symbols that are not understood by the child or are not culturally sensitive. This is an important consideration for conducting vision screening programs with New American, immigrant, or culturally and linguistically diverse populations.
  • Optotypes should blur equally. When a symbol cannot be correctly recognized, the symbols ‘blur to zero’ or transform into circles called "rings" or "balls”.
  • Ideally, the visual acuity charts should have either a proportional layout (the space above the line is equal to the size of the letter below) or have a linear layout (specific spacing between optotypes but not the lines). Due to low testability, proportional charts are not recommended as the first choice for children under 5 years old.
  • To achieve both high standards of testability and sensitivity, the visual acuity charts with the 50% spaced rectangle around each line of letters or symbols are recommended. These rectangles create a ‘crowding phenomena’, which is considered by the National Institutes of Health’s Vision in Preschoolers (VIP) study as the best strategy to detect amblyopia.

Question 10. If you are screening a child who does not speak English, regardless of age, can you use the LEA or HOTV?

A. Yes, as long as you keep it a matching symbol test and do not ask the child to name the letter or symbol.

Question 11. What visual acuity charts do NOT meet the criteria for inclusion in the MDH Vision Screening Guidelines?

A. Examples of visual acuity charts not recommended by the MDH for screening children in Minnesota are pictured below:

Visual Acuity Charts

Question 12. What are the pass criteria for the recommended visual acuity charts?

A. The pass criteria for:
Children ages 3 - 4 years: 10/20 or better in each eye without a 2-line difference
Children ages 5 years and older: 10/15 or better in each eye without a 2-line difference

Question 13. What visual acuity chart is recommended for screening vision in children six years old and older?

A. The 20 foot Snellen chart or the Sloan Charts are recommended. The Pass criteria is 20/30 or better without a 2-line difference

Snellen Chart #600727Snellen Chart #600727
Sloan Chart # 600725 (Linear Spaced Chart)Sloan Chart #600725

Question 14. Some nurses have reported problems with higher than expected re-screening rates using the 20-foot vision chart with 1st grade children. What can be done?

A. There are three options: 1) buy a 10 foot letter chart; 2) have a volunteer point at the line to be read on the edge of the chart (not individual letters); or 3) hold a piece of paper under the line so it is clear to the child which line is to be read. REMEMBER: Individual letters cannot be isolated.

Question 15. I know that 20 feet is the ideal distance to test visual acuity for children age 6 and older, I simply do not have the space. What can I do to accommodate these limitations in my facility?

A. A 10-foot equivalent chart is available from several suppliers that could be used in vision screening environments when space is a factor. (see below for example)

#600723 (Sloan, Linear Spaced Chart)#600723 (Sloan, Linear Spaced Chart)

Question 16. What if a child does not pass the 20/25 line but can read the 20/20 line? Do I then have them read the line below the 20/20 to check for a 2 line difference?

A. No. If a child gets a line on the chart incorrect, stop screening and record the vision at that point. During screening it is not necessary to have the child read below the 20/20 line.

Question 17. In the past, the MDH used to make small index cards to match the visual acuity charts; will this continue to be available?

A. Yes and they will be available on the MDH Web site at in April 2006. This website is

Question 18. What screening instruments can I use to check near vision?

A. The MDH recommends screening with the plus lens.

Other Visual Screening Instruments

Question 19. I understand that there are other screening protocols besides visual acuity charts, what are they?

A. Visual acuity charts screen for near sightedness, far sightedness, astigmatism, and anisometropia (visual acuity differences between the two eyes). However, it is also important to screen for muscle balance deficiencies with corneal light reflection and the cross cover test.

MDH recommends the Random Dot E or the Stereopsis butterfly to check for stereopsis.

Question 20. Can I just test the children with the visual acuity charts and skip the muscle balance testing (i.e., observation, corneal light reflection and cross cover tests)?

A. No. The Early Childhood Screening program is required for public school entrance per Minnesota Statutes 2003, 121A.17 subd.1.

All screening components shall be consistent with the standards of the state commissioner of health for early developmental screening programs. It is very important that muscle balance screening is provided to children participating in the Early Childhood Screening program, as well as students in first and third grades. The early childhood years and the early elementary years are critical touch points to screen for amblyopia risk factors.

Question 21. What are the MDH recommendations for testing for color vision deficiencies?

A. It is recommended that male students enrolled in first grade are screened for color vision deficiencies since there is a statistically significant higher incidence of color vision deficiencies among males. It is optional for school districts to screen female students for color vision deficiencies.

Question 22. Are there any special hints to help with screening 1st grade children for color vision problems?

A. If you are using the Ishihara book, have them trace the lines (with a clean water color paint brush) in the back of the book. The instructions for pass/re-screen are found in the back of the book. If they have normal color vision they will see the same lines as you do, providing you have normal color vision. Some of you have asked about having the child trace the numbers. This is okay, but if they only see one of the numbers, e.g., 7 on the page with the number 74, the question or pass or re-screen is unclear. You may want to invest in one of the books made for unlettered persons or the new Waggoner color vision book which is specifically designed for screening young children.

Question 23. Why is stereopsis screening optional?

A. If time is an issue, then it is an optional screening procedure for the children aged 3 years through 3rd grade. If there is time and the stereopsis equipment is available the procedure should be done on all children at the recommended ages.

Age Appropriate Screening

Question 24. What kind of problems can I anticipate finding at different ages?

A. Infants to age 4 months: It is not uncommon to have an occasional eye that crosses at this age. A child should be evaluated by an eye professional if the eye is fixed in a crossed position. An immediate referral to an eye professional should be made for any red reflex abnormalities.

Infant’s age 6 to 12 months: Usually have a high incidence of hyperopia and astigmatism that usually resolves without treatment.

Children ages 4 months to 3 years: It is important to screen for problems such as strabismus (crossed eyes) in very young children. Forty percent of children with strabismus are at high risk for developing amblyopia.

For children ages 8 and older: During the school-age years, it is important to screen for myopia, as 20 % of these children are so nearsighted that they will require corrective glasses. Generally, school-age students do not report visual problems, as they may have grown accustomed to blurred vision.

Question 25. What ages/grades does MDH recommend vision screening be provided through Head Start and the Child and Teen Checkups/EPSDT Programs?

A. For Child and Teen Checkups, MDH recommends following Department of Human Services (DHS) and MDH requirements of:

  • Subjective screening - Children must be screened for family history of early onset vision problems and ocular abnormalities, as well as maternal and neonatal infection. A child must be observed for proper eye alignment, pupillary reflex, the presence of nystagmus, and muscle balance, which includes an examination for esotropia, exotropia, phorias, and extraocular movements. The external parts of a child's eyes must be examined, including: the lids, conjunctiva, cornea, iris and pupils. Until visual acuity can be obtained, observe the child's eyes for ability to track, pupillary response to light, and retinal reflex symmetry. The child, parent or guardian must be asked if there are concerns about the child's vision.
  • Objective screening - Use standardized visual acuity charts at ages 3, 4, 5, 6, 8, 10, 12, 14, and 18 years. For 16 and 20 year olds, if objective screening was not conducted at the previous checkup, acuity testing is recommended.

For 3-5 year old children enrolled in Head Start, the MDH recommends following the Minnesota Department of Education (MDE) vision screening requirements for the Early Childhood Screening program. For 0-3 year old children enrolled in Early Head Start, MDH recommends that these programs follow the Child and Teen Checkups/EPSDT vision screening schedule described above.

Referral and Follow up

Question 26. How do I know if I’m over or under referring for possible vision problems?

A. The MDH receives vision screening reports from some school and public health agencies voluntarily in grades K and older. The MDH examines national data as well. Data indicates that typically a 12% vision rescreen rate and a 7% vision referral rate occurs in Minnesota as well as the national level.

New Technology

Question 27. How can technology be used in vision screening programs?

A. The vision screeners (examples below) are appropriate for vision screening. However, caution needs to be exercised when using the equipment with young children as they have been able to peak on the older equipment as a result of the equipment’s ergonomics. The older equipment is not designed to accommodate the small head of young child to the viewer. MDH also recommends testing color vision separately, as the manual color vision books have higher sensitivity. The visual acuity referral criteria are the same as for the vision charts (20/40 for age 4 and under, 20/30 for age 5 and older). Pictured below are the Titmus and Keystone screeners as examples. Other brands are also available. The price range is $1,400.00-$1,700.00.

Titmus and Keystone vision screeners

Question 28 . What is the MDH recommendation for the SureSight Vision Screener?

A. The SureSight Vision Screener has demonstrated some promising preliminary results in the National Institutes of Health’s Vision in Preschoolers Study. However, this 5-year study is still in process and final recommendations will not be published until the study is completed. Since the final study results are not available, the SureSight Vision Screener is not a recommended tool in the MDH Vision Guidelines. However, information regarding the SureSight Vision Screener will be provided in the 2006 MDH Vision Screening Guidelines. This information will include suggested recommendations on how to use the SureSight Vision Screener. The MDH recommendations are a modification of the current manufacturer’s recommendations. These modifications are based on the experience of various agencies that have successful results with the equipment after making the modifications to the manufacturer’s recommendations (i.e., identifying true positives from their referral results). The MDH does not recommend new purchases of the SureSight Vision Screener until further data about the instrument’s efficacy are available and the new VIP software is added. The price is approximately $4,000.00.

Suresight Vision Screener

Vision Screening Resources:

Question 29. Are there Minnesota vision resources on the Web?

A. Yes. All of vision screening forms and resources are available on the MDH Web site at The MDH Web site will be updated with new materials in early April 2006 to reflect changes to the Vision Screening Guidelines.

Question 30. We have a lot of students who are English Language Learners. What vision screening forms or materials are available in other languages?

A. The MDH vision screening referral letters are available in Hmong, Laotian, Russian, Spanish, and Vietnamese.

Question 31. In light of the 2006 vision guidelines, do we have to replace all the vision charts that we are currently using?

A. No, but you are strongly encouraged to purchase the new 50% reduced rectangle LEA and/or HOTV charts for pre-school and kindergarten screening now. Replace your other vision charts as you need to.

Question 32. Where can visual acuity charts and equipment be purchased?

A. The following is a partial listing of companies that supply vision screening instruments recommended by the MDH:

Good-Lite Company
Phone: 1-800-362-3860

School Health Corporation
Phone: 1-800-323-1305
This vendor has developed, on their own, a special pricing list.

MacGill Discount School Nurse Supply
Phone: 1-800-323-2841

School Nurse Supply, Inc.
Phone: 1-800-485-2737*

* This vendor may not have the 50% rectangle charts or the Minnesota Early Childhood Screening Flipchart as of (3/06)