A pensioner still remains partially sighted more than a month after he was sprayed in the face with a mystery substance by balaclava-clad burglars.

n elderly couple in their 70s, who have lived in Letchworth for more than 40 years, were the victims of an aggravated burglary which saw them both needing hospital treatment.

If the effects of the man’s injury fail to heal, he may have to have an operation at the specialist Moorfields Eye Hospital in London, which he has already visited on several occasions since the attack.

In the attack three men wearing balaclavas knocked on the front door of the couple’s house in Jackmans Place, confronted the man who opened the door and forced their way in past him.

They then sprayed him in the face and took his watch, before spraying his wife in the face and taking off her earrings, bangles and ring.

One of the men – who is believed to have spoken in Punjabi – then searched an upstairs bedroom before all three men left via the front door.

A granddaughter of the couple, who wishes to remain anonymous, said: “When the men tried to attack my grandmother, my grandfather tried to protect her – I think it was just a natural instinct because that is the sort of man he is, but he has been left with compromised vision.

“He has suffered from arthritis in the past and should never have been put in the situation where he has to physically defend his family.

“My grandparents keep themselves to themselves, but they are very family-orientated.

“They have always thought that Letchworth is a very quiet place where this sort of thing doesn’t happen, but now they are scared and they don’t feel safe.

“They are gradually getting over the shock, but it will take time. My grandparents’ first language is Punjabi, and it was my grandmother who thinks she heard one of the men speaking Punjabi.”

Anyone with information about the incident – which took place between 8pm and 8.15pm on Saturday, March 28 – should call the police non-emergency number 101 or Crimestoppers anonymously on 0800 555 111.