The goal of this double-masked randomised controlled trial (RCT) is to assess the symptoms of visual stress (VS), reading speed and changes in behaviour / academic performance, when wearing optimal Precision Tinted Lenses compared to sub-optimal Precision Tinted Lenses (PTLs). In participants ages 9-18 years.

Participants, parents and researchers will be masked until the end of the trial.

Participants will be randomised into two groups A and B. 50% of participants will receive the optimal PTL where the other 50% will receive the sub-optimal PTL.

Participants will be asked to wear the PTLs for one month. Followed by one month of no wear. After which, participants will receive the second pair of PTLs to wear for one month.

Participants will need to fill out a symptom dairy everyday from the day of recruitment until the end of the trial. A symptom questionnaire will need to be filled out as baseline at recruitment and the end of each month of wear. An academic behaviour survey will also need to be filled out at baseline by parents and teachers at recruitment and the end of each month of wear.

At the end of the three months unmasking will occur and participants will be given the PTL that demonstrate the greatest reduction in VS.

The ARUTIS study is a double-masked randomised controlled trial (RCT) having a double-masked crossover (AB/BA) design. The study aims to assess the symptoms of visual stress (VS), reading speed and changes in behaviour / academic performance, when wearing optimal Precision Tinted Lenses compared to sub-optimal Precision Tinted Lenses (PTL). The PTLs will be prescribed by the Intuitive System.

A total of 120 participants aged 9-18 years with symptoms of VS will be recruited from the Anglia Ruskin University eye clinic. Participants will be randomised into either Group 1 (receiving the two interventions A (optimal tint) and B (sub-optimal) in the order AB) or Group 2 (receiving the two interventions in the order BA).

The initial pair of PTLs will be given to participants for a one-month wearing period. Subsequently, a one-month washout period is observed, after which participants receive the second pair of PTLs for one-month. Participants are required to fill out a symptom diary daily. A symptom questionnaire will need to be filled out as baseline at recruitment and the end of each month of wear. An academic behaviour survey will also need to be filled out at baseline by parents and teachers at recruitment and the end of each month of wear. Following the three months, a head-to-head comparison and unmasking will occur.

Participants will be given the Precision Tinted Lenses that demonstrate the greatest reduction in VS. The study will combine quantitative and qualitative data collection. The primary outcome measure is comparing symptom scores with questionnaires and symptom diaries reported under two different treatment conditions. The secondary outcome measures will be evaluated. in two ways: change in reading speed and results from academic behaviour surveys.

Inclusion Criteria:

1. Age 9-18y.
2. Meet diagnostic indicators for visual stress (see below)
3. Consent (parent and participant to attend for optometric testing and participate in research.
4. Do not anticipate moving from the area in the next 3 months

Diagnostic indicators for visual stress

At least three of the following six typical symptoms:

1. Words Move
2. Words Merge
3. Patterns or shadows in text (e.g., "rivers")
4. Text seems to stand out in 3-D above the page
5. Words or letters fade or darken
6. Discomfort with certain artificial lights and flicker

And "At least two of the following three signs from investigations:

1. Voluntary unprompted use of an overlay for 3 months or more
2. Overlay improves performance at the WWRT BY ≥15%
3. PGT result >3 with mid spatial frequency grating.

Exclusion Criteria:

1. History of wearing precision tinted lenses.
2. Ocular pathology, systemic pathology that is likely to worsen in the timescale of the study or cause transient blur (e.g., diabetes) or photosensitive epilepsy

The study will conform to the tenets of the Declaration of Helsinki and will be registered in a clinical trials registry. When the analysis is complete, anonymised data will be stored in a publicly accessible data repository. Full informed consent will be obtained from participants and parents/guardians. Ethical approval was granted from the Anglia Ruskin University Faculty Research Ethics Panel (FREP).

Data will be available after the trial has been completed. Which will be in approximately 12 months.

Data will be available for as long as necessary.