Pseudomyopia is a condition that (to the patient) resembles myopia (i.e. can see at near but distance appears blurred) but arises due to inappropriate contracture of the ciliary muscle as opposed to the standard causes of myopia (axial - eye grows longer than focal range of refractive apparatus, refractive - lens/cornea too strong & index - cataract formation). In normal viewing, the ciliary muscle is relaxed when viewing at distance and contracted when viewing at near. When contracted this leads to the crystalline lens (sits behind the coloured iris) to become more convex increasing the focal power of the eye to allow near viewing. This process is known as ocular accommodation. In Pseudomyopia this muscle becomes contracted in the “relaxed” state leading to an inappropriate accommodative response, where the eye focusses for near when the patient wants to view distance targets. This often occurs after prolonged near work. If a clinician does not realise this is Pseudomyopia, they can prescribe “correction” that will further stimulate the process. This can continue until a break down occurs between the accommodative and vergence systems giving rise to double vision. In the short term, this is of limited risk of harm to the patient - if properly managed. I have seen a fair few cases like this who have attended (mainly) corporate practices and have 2–3 prescriptions issued before double vision occurs, following which they are referred for neurological assessment which is clear (as this isn’t a neuro issue), before being referred to another optometrist for a second opinion. These cases can be managed by removing the stimulus to accommodate (often through cycloplegia) and prescribing low degree of convex lens prescription (i.e. a reading or learning lens) to stop the patient falling into the cycle again. This is followed up with orthoptic (accommodative) management to help the patient control their own focusing system and remove the dependence on the reading lens. If this is identified sooner (i.e. before double vision occurs) then the cycloplegia can be avoided and the condition managed through other means such as bifocals/PALs and orthoptics to achieve the desired outcome. In the long term? Unfortunately, binocular vision at large is an under-researched area (to qualify - studies in this area are often ill-selected, the condition ill-defined (as many of these overlap - so difficult to isolate and treat one condition), unmasked, with small numbers of participants). This means that while studies can give an indication to best practice, it is often more challenging to definitively state the most likely outcomes. From what information is known, and from clinical experience it seems that Pseudomyopia if unmanaged does frequently progress on to true myopia. There is a lot of research into myopia going on, much of which supports the view of myopia being a family of conditions with similar outcomes rather than just one condition. As I have discussed elsewhere this fall into the family of myopia that when managed with bifocals/multifocal/orthoptics the condition generally resolves (in this case without true myopia development) but left uncorrected true myopia seems to arise to adapt to relieve the stress on the visual system.
