One in 10 organ donors opts out of donating their eyes, figures show.
Data from NHS Blood and Transplant (NHSBT) show that 10.6% of people on the organ donor register are willing to donate organs including hearts, livers and kidneys but they choose not to donate their eyes.
As well as donors being less forthcoming about donating their eyes, families of donors also sometimes decline to consent to the donation of their loved ones' eyes.
This could be due to the old adage of "eyes being the window to the soul", one expert said.
The so-called "yuck factor" may also be at play, said Emma Winstanley, lead nurse for NHSBT's Tissue and Eye Services.
But donating one's eyes can help "transform" the lives of people in need of sight-saving operations, she said.
One donor can help restore or improve the sight of up to 10 people.
But figures show that NHS eye banks are running short of what is needed.
NHSBT needs around 350 corneas in its eye banks - situated in Manchester and Bristol - to meet patient need.
But from the start of 2018 until November 23, the average number of corneas in the eye banks at any given time was 307.
Paediatrician Dr Victoria Parsonson almost lost her sight before she received a cornea transplant.
The 35-year-old, from Birmingham, said she was "given the gift of sight" and the operation "completely changed" her life.
She was diagnosed with keratoconus, a progressive eye disease which causes distorted and blurred vision, when she was 16.
"I was devastated, all I ever wanted to be was a doctor," she said.
But in 2001 she had the cornea transplant at Bristol Eye Hospital.
Dr Parsonson added: "Having a transplant completely changed my life.
"It helped me to help other people.
"I like to think that I have been given the gift of sight and I hope in my career I am able to also give something back to people.
"My donor and their family are amazing and I can't thank them enough for what they have done for me."
In the last year 3,504 people in England have had their sight restored through cornea transplants.
Ms Winstanley, of NHSBT's Tissue and Eye Services, told the Press Association: "It is a phenomenon which we call the 'yuck factor' - some people are squeamish about eyes.
"So what we find is some people are willing to donate organs and other tissues like heart valve, bone and tendons, but sometimes when you ask a family member about eyes they can say 'You can have anything you want, but not the eyes'.
"It's within our culture about eyes being the 'windows to the soul' but actually, when you really think about it, you could be saving somebody's sight or be giving them the gift of sight.
"That kind of counteracts that feeling."
NHS Blood and Transplant needs 90 donations a week to meet the demand for sight-saving transplants.
The cornea - the clear tissue on the front of the eye that help the eye to focus light - is one part of the eye that can be donated.
The sclera, the white part of the eye, can also be donated for reconstruction surgery.
Other tissue is used for research and development.
But the eye is never transplanted whole.
People can donate their corneas up to 24 hours after they die and, unlike organ donation, it is not necessary for them to die in a hospital intensive care unit or A&E department to become a donor.
Donation can take place after death in hospital, in hospices or in funeral home.
A wider pool of people can also be eye donors, including most cancer patients and people who have eye problems themselves such as the short-sighted.
And donors can be almost any age, with an upper limit of about 85 in Britain, which is around the time the cell count drops on the corneas.
To find out more visit: https://www.organdonation.nhs.uk/