Bouldoukian J, Wilkins AJ, Evans BJ Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties. Ophthalmic Physiol Opt. 2002 Jan;22(1):55-60.
Evans BJ, Stevenson SJ The Pattern Glare Test: a review and determination of normative values. Ophthalmic Physiol Opt. 2008 Jul;28(4):295-309. doi: 10.1111/j.1475-1313.2008.00578.x.
Monger L, Wilkins A, Allen P Identifying visual stress during a routine eye examination. J Optom. 2015 Apr-Jun;8(2):140-5. doi: 10.1016/j.optom.2014.10.001. Epub 2014 Nov 11.
Wilkins AJ, Jeanes RJ, Pumfrey PD, Laskier M Rate of Reading Test: its reliability, and its validity in the assessment of the effects of coloured overlays. Ophthalmic Physiol Opt. 1996 Nov;16(6):491-7.
Efficacy of Coloured Overlays and Lenses for Adults With Reading Difficulty
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
