When a person changes fixation from one target, at a given fixation distance, to another target, at an alternate fixation distance, a number of ocular systems need to be altered in order to maintain clear single binocular vision. One such system is that of accommodation, involving either positive or negative accommodation 1 . When viewing an object at six meters, a distance known optometrically as optical infinity, it is assumed that parallel light rays enter the eye. For an emmetrope this results in zero accommodative demand and therefore zero accommodation. When viewing an object closer than 6 meters positive accommodation is required. This involves intraocular lens changes which ultimately increase the refractive power of the eye, allowing the rays to form a point focus on the retina. The opposite process, negative accommodation, occurs when an object is fixated further away from some near fixation point. Accommodation can therefore be thought of as the process by which the refractive power of the eye is altered to ensure a clear retinal image 1 .It should also be noted that a change in the position of the visual axes must also take place 1 . This occurs to ensure that a single image of the target is seen. The change in relative position of the visual axis is called convergence when the angle formed by the visual axes increases, and divergence when this angle decreases 1 .When a person fixates a near target an additional process takes place, that is, pupillary constriction. This occurs together with accommodation and convergence, and alters the depth of focus 1 . These three sub-systems work together as a synkinesis known as the near triad 1, 2 .One should not forget the fact that the processes mentioned above are very complex and involve numerous pathways, the details of which are little known. As a result it is easy to understand that many problems can occur in each process, resulting in visual problems. This paper serves to address some of those visual problems. AccommodationThe amplitude of accommodation represents the closest near focusing response that can be produced with maximal voluntary effort in the fully corrected eye 2 . From around five years of age to around 52 years of age, the accommodative amplitude progressively decreases at a rate of approximately 0.30 D per year 2 . Various theorists attribute the loss of accommodation to changes in the elastic properties of the lens, changes in the action of the ciliary muscle, or both 3 . The anterior chamber depth, shape of the lens, refractive index and position of the lens surfaces change with age, affecting the accommodative process 4 . This leads to the development of presbyopia. The amplitude of accommodation inevitably decreases from 11 D or more at age 10 to nearly 0 D by age 70 years. This means that an emmetropic child can focus an object as close as 10 cm, while an older adult must move objects at least a metre or more away to see them clearly 3 . †