Introduction: There is evidence that certain measures of visual function show some type of relationship between right and left eyes in the same individual. Similarly, particular ocular maladies may be related, or be symmetric, in the right and left eyes of the same person. There is also evidence to suggest that certain relationships do not exist between eyes in an individual. For example, diseases such as glaucoma are often asymmetric in their progression in the two eyes of an afflicted individual. Inter-ocular mirror symmetry between right and left eyes, when considering ocular wavefront aberrations (WAs), has been shown to exist by some authors. This study investigates whether mirror symmetry of high order aberrations (HOAs) exists between the right and left eyes in a cohort of South African subjects.Method: Third to 5 th order Zernike coefficients

Oculomotor dysfunction may originate from physical, physiological or psychological causes and may be a marker for schizophrenia or other disorders. Observational tests for oculomotor dysfunction are easy to administer, but are subjective and transient, and it is difficult to quantify deviations. To date, video-based eye tracking systems have not provided a contextual overview of gaze data that integrates the eye video recording with the stimulus and gaze data together with quantitative feedback of metrics in relation to typical values. A system was developed with an interactive timeline to allow the analyst to scroll through a recording frame-by-frame while comparing data from three different sources. The visual and integrated nature of the analysis allows localisation and quantification of saccadic under- and overshoots as well as determination of the frequency and amplitude of catch-up and anticipatory saccades. Clinicians will be able to apply their expertise to diagnose disorders based on abnormal patterns in the gaze plots. They can use the line charts to quantify deviations from benchmark values for reaction time, saccadic accuracy and smooth pursuit gain. A clinician can refer to the eye video at any time to confirm that observed deviations originated from gaze behaviour and not from systemic errors.

Background: Staphylococcus aureus is a common commensal on skin and mucosal surfaces; its contact with the eye may cause a variety of ocular inflammations and infections such as blepharitis, conjunctivitis and keratitis, amongst others. Soft contact lenses provide perfect conditions for the breeding of certain pathogens, and disinfecting solutions for contact lenses are therefore of utmost importance. These solutions should be effective in inhibiting the growth of a variety of pathogens to protect the user from ocular infections.Aim: To highlight the need for clinicians to be aware of the effects of various recommended disinfecting contact lens solutions.Method: Three popular disinfecting contact lens solutions readily available in South Africa were chosen. These and a control solution (saline) were prepared and inoculated with S. aureus to evaluate the antimicrobial efficacy of each solution. The primary stand-alone test was used to evaluate the solutions according to the ISO standard specifically for this purpose.Results: The test results indicated that two of the solutions met the ISO standards; the third failed. Of the two that passed the test, only one showed the required 3-log reduction after 30 minutes, as per the ISO standard, although this solution is marketed as a ’10 minute system’.Conclusion: It is important for clinicians to be aware of the complications that may be caused by contaminated solutions, and patients should be warned about the effects thereof. To ensure healthy eyes for our patients, sufficient knowledge regarding the efficacy of recommended multipurpose solutions is necessary. Solutions that meet ISO standards promote good ocular health and ensure sufficient cleaning and disinfecting of contact lenses.

This article is the second in a series of two articles, which provides a discussion of the factors that may possibly contribute to variable results when wavefront aberrations of the human eye are measured. Some of the factors discussed in this article are the influences that refractive errors (specifically myopia and astigmatism), pupil diameter, accommodation of the crystalline lens, age, mydiatric drops and the integrity of the tear film may have on these wavefront measurements. The first article in the series explained the general principles of higher order aberrations (HOAs), as well as HOAs of importance in the eye and the measuring apparatus used to measure HOAs of the eye.Keywords: wavefront aberrations; aberrometry

This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs) of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer