Most people who reach the Rehabilitation Department conflate three different things: the expert opinion they bring, the medical committee that sets the percentage, and the appeal that can follow. This page is about the middle one — the medical committee itself: what happens in the room, on what basis the percentage is cut, and where the decisions that move it most actually sit. The framework for the expert opinion is on eye expert opinion for the Ministry of Defence, and the appeal deadlines and rules are on appealing a medical committee.
First recognition, then the percentage — two separate stages
The process at the Rehabilitation Department divides in two, and many do not separate them. In the first stage, the benefits officer decides whether the injury is service-connected — that is recognition. Only afterwards, in the second stage, does the medical committee — a panel of specialist physicians — set the disability rating according to the impairment clauses, and whether it is temporary or permanent.
That separation is not a technicality. One can be recognised as service-injured and still come out at 0%, if the committee holds that the impairment does not reach the rated threshold. Recognition opens the door; the committee decides what was found behind it.
The heart of the committee: how the impairment attaches to service
This is the decision that moves the percentage more than any argument over a tenth of a line of acuity, and it almost always escapes the examinee’s notice. An impairment can attach to service in three ways, each with a different meaning for the percentage.
An impairment caused by service is the direct one. A penetrating eye wound in training, a chemical corneal burn, radiation damage — these are attributed to service in full, and the percentage set is counted as it stands.
An aggravated impairment is a pre-existing condition, unrelated to service, that the service merely worsened. And here the mechanism that cuts comes in: the benefits officer determines what portion of the disability stems from service and what from the prior condition, and only the service portion enters the calculation. The official example shows the force of this: if half the condition is found to predate service, and the committee sets 40% disability, only 20% is actually counted. Half the percentage is erased not because of the finding, but because of the question of origin.
A consequential impairment (Regulation 9) is a new impairment derived causally from an already-recognised disability. In ophthalmology this is a familiar course: a recognised penetrating injury that later brings on traumatic glaucoma, a cataract or a retinal detachment — the complication itself can be recognised as a further consequential impairment, provided the causal link to the original disability is direct and documented, not merely statistical likelihood or age-related wear.
The fault line of aggravation runs in a predictable place. Diseases with a degenerative or genetic component are its battleground: keratoconus discovered in service but genetically present beforehand, glaucoma with a family history, hereditary retinal degeneration. There the question “how much of this is the service” becomes central, and there a poorly documented file quietly loses half the percentage.
The practical conclusion: where a condition can be argued to predate service, the medical documentation must speak not only to the severity of the impairment but to the course of its worsening — when it began, how much it progressed during service, and what links that progression to the conditions of service. That is precisely what an expert opinion is built to provide.
Temporary or permanent — and why it is common in ophthalmology
The committee also decides whether the rating is temporary or permanent. A temporary rating carries with it a date for re-examination, at which the percentage will be set afresh. A permanent rating carries no such date.
In ophthalmology, temporary is more common than usual, because a large share of conditions are still in motion at the time of the committee. After surgery — cataract, corneal transplant, retinal surgery — the state stabilises over weeks to months. A cornea heals. Medical treatment of glaucoma is still changing the visual field. There is no logic in fixing a percentage on a picture that is still moving, so the committee assigns a temporary rating and a date to look again. It is worth remembering that temporariness works both ways: a condition that has improved will lower the rating, and one that has worsened will raise it.
Worsening: the door that stays open, with a condition
A condition that deteriorated after a rating was already set is not the end of the story. One can file a worsening claim and request a re-examination — on one clear condition: that at least six months have passed since the previous rating was set.
There is a detail here that surprises many: the cost of the re-examination is borne by the applicant, unless the benefits officer decides otherwise, or the examination shows the rating did in fact change. In other words, a well-founded worsening claim — one resting on documentation that shows real deterioration — not only improves the odds, it may also return the cost of the examination.
In ophthalmology this is the most important door, because a substantial share of rated conditions are progressive by nature: keratoconus that keeps changing, a glaucomatous field that gradually closes, a maturing cataract, a spreading retinal degeneration. Anyone rated at an early stage of a progressive disease should know this mechanism exists — and document the deterioration as a sequence, not as a one-off on the eve of the examination.
What to bring to the eye committee
- A series of tests, not a single date. Corrected acuity, visual field and corneal mapping measured on more than one occasion — to show a stable state or a course, not a point in time.
- Documentation from service and from before it, where relevant to the caused/aggravated question. If there is a claim that the condition predated service, the documents showing the state on entry to service are what decide how much of it is erased.
- Printed reliability indices on visual field tests — a noisy chart invites refusal.
- A sequence over time for worsening — deterioration documented across months reads differently from deterioration declared the day before the examination.
- Physician letters in the language of the schedule — framing the extent of the structural damage, not only the severity of symptoms.
The full framework for preparing an opinion for this track is on eye expert opinion for the Ministry of Defence. If a decision has already been issued and does not reflect the situation — the deadline for the upper medical committee, and its rules, are on appealing a medical committee.
Bottom line
The Ministry of Defence medical committee is not a place where percentages are merely counted off a schedule. Two decisions made there — whether the injury is caused or aggravated, and whether the rating is temporary or permanent — change the outcome no less than the clinical finding itself, and sometimes more. Whoever walks into the room understanding those two decisions knows what is really being weighed there: not only how much he sees, but how much of it is the service, and how much of it is still ahead.
Frequently asked questions
When does the committee split the percentage, and what is deduction of a prior condition?
When the impairment is aggravated — a pre-existing condition, unrelated to service, that the service merely worsened. In that case the benefits officer determines what portion of the disability stems from service and what portion from the prior condition, and only the service portion enters the calculation. If half the condition is found to predate service and the committee sets 40%, only 20% is counted. For the very same finding, that decision can halve the percentage. An impairment caused entirely by service, by contrast, is attributed to it in full; and a consequential impairment under Regulation 9 is a separate question — a new complication derived from an already-recognised disability.
Can I request a re-examination if my condition worsened after the committee?
Yes, through a worsening claim — but only if at least six months have passed since the previous rating was set. Know this in advance: the cost of the re-examination is borne by the applicant, unless the benefits officer decides otherwise or the examination shows the rating did in fact change. In ophthalmology this matters especially for progressive diseases — keratoconus that keeps deteriorating, a glaucomatous field that keeps closing, a maturing cataract.
What is the difference between a temporary and a permanent rating?
If the committee sets a temporary rating, a date is set with it for a re-examination at which the rating will be determined afresh. A permanent rating carries no such date. In ophthalmology a temporary rating is common when the condition has not yet stabilised — after surgery, during corneal healing, or while treatment is still changing the picture. There is no sense in fixing a percentage on a condition that is still moving.
How does the Ministry of Defence eye committee differ from the National Insurance one?
In the schedule. The Ministry of Defence tests include clauses that do not exist at National Insurance — glaucoma (clause 58, 5%/10%), cataract (clause 62(e)/67, 5%/10%), conjunctivitis and blepharitis (clause 59, abolished at National Insurance in 2012). The principle behind them all is the same: at the Ministry of Defence the diagnosis carries value of its own, and the damage to field and acuity accumulates on top of it. At National Insurance only the functional damage is measured.
